diff --git a/src/bootstrap/channel.rs b/src/bootstrap/channel.rs
index be2b0f36d14a7..f9d3b454246b1 100644
--- a/src/bootstrap/channel.rs
+++ b/src/bootstrap/channel.rs
@@ -13,7 +13,7 @@ use build_helper::output;
 use crate::Build;
 
 // The version number
-pub const CFG_RELEASE_NUM: &str = "1.44.0";
+pub const CFG_RELEASE_NUM: &str = "1.45.0";
 
 pub struct GitInfo {
     inner: Option<Info>,
diff --git a/src/liballoc/lib.rs b/src/liballoc/lib.rs
index a2071844d5dac..f422c3f66e147 100644
--- a/src/liballoc/lib.rs
+++ b/src/liballoc/lib.rs
@@ -99,7 +99,7 @@
 #![feature(internal_uninit_const)]
 #![feature(lang_items)]
 #![feature(libc)]
-#![cfg_attr(not(bootstrap), feature(negative_impls))]
+#![feature(negative_impls)]
 #![feature(new_uninit)]
 #![feature(nll)]
 #![feature(optin_builtin_traits)]
diff --git a/src/liballoc/rc.rs b/src/liballoc/rc.rs
index fb9f5faa018a4..8144fe0128ee8 100644
--- a/src/liballoc/rc.rs
+++ b/src/liballoc/rc.rs
@@ -279,7 +279,6 @@ struct RcBox<T: ?Sized> {
 /// type `T`.
 ///
 /// [get_mut]: #method.get_mut
-#[cfg_attr(all(bootstrap, not(test)), lang = "rc")]
 #[cfg_attr(not(test), rustc_diagnostic_item = "Rc")]
 #[stable(feature = "rust1", since = "1.0.0")]
 pub struct Rc<T: ?Sized> {
diff --git a/src/liballoc/sync.rs b/src/liballoc/sync.rs
index cde412bee78d9..adce23c42c0e8 100644
--- a/src/liballoc/sync.rs
+++ b/src/liballoc/sync.rs
@@ -207,7 +207,6 @@ macro_rules! acquire {
 /// counting in general.
 ///
 /// [rc_examples]: ../../std/rc/index.html#examples
-#[cfg_attr(all(bootstrap, not(test)), lang = "arc")]
 #[cfg_attr(not(test), rustc_diagnostic_item = "Arc")]
 #[stable(feature = "rust1", since = "1.0.0")]
 pub struct Arc<T: ?Sized> {
diff --git a/src/libcore/clone.rs b/src/libcore/clone.rs
index 6165941eb3dae..7784ec687ea9a 100644
--- a/src/libcore/clone.rs
+++ b/src/libcore/clone.rs
@@ -231,6 +231,5 @@ mod impls {
 
     /// Shared references can be cloned, but mutable references *cannot*!
     #[stable(feature = "rust1", since = "1.0.0")]
-    #[cfg(not(bootstrap))]
     impl<T: ?Sized> !Clone for &mut T {}
 }
diff --git a/src/libcore/convert/num.rs b/src/libcore/convert/num.rs
index 66ae760fc1f79..6dd0522f7f610 100644
--- a/src/libcore/convert/num.rs
+++ b/src/libcore/convert/num.rs
@@ -28,14 +28,7 @@ macro_rules! impl_float_to_int {
                 #[doc(hidden)]
                 #[inline]
                 unsafe fn to_int_unchecked(self) -> $Int {
-                    #[cfg(bootstrap)]
-                    {
-                        crate::intrinsics::float_to_int_approx_unchecked(self)
-                    }
-                    #[cfg(not(bootstrap))]
-                    {
-                        crate::intrinsics::float_to_int_unchecked(self)
-                    }
+                    crate::intrinsics::float_to_int_unchecked(self)
                 }
             }
         )+
diff --git a/src/libcore/future/mod.rs b/src/libcore/future/mod.rs
index a6b769147d068..e7f681c2e9450 100644
--- a/src/libcore/future/mod.rs
+++ b/src/libcore/future/mod.rs
@@ -2,7 +2,6 @@
 
 //! Asynchronous values.
 
-#[cfg(not(bootstrap))]
 use crate::{
     ops::{Generator, GeneratorState},
     pin::Pin,
@@ -24,16 +23,13 @@ pub use self::future::Future;
 /// It also simplifies the HIR lowering of `.await`.
 #[doc(hidden)]
 #[unstable(feature = "gen_future", issue = "50547")]
-#[cfg(not(bootstrap))]
 #[derive(Debug, Copy, Clone)]
 pub struct ResumeTy(NonNull<Context<'static>>);
 
 #[unstable(feature = "gen_future", issue = "50547")]
-#[cfg(not(bootstrap))]
 unsafe impl Send for ResumeTy {}
 
 #[unstable(feature = "gen_future", issue = "50547")]
-#[cfg(not(bootstrap))]
 unsafe impl Sync for ResumeTy {}
 
 /// Wrap a generator in a future.
@@ -43,7 +39,6 @@ unsafe impl Sync for ResumeTy {}
 // This is `const` to avoid extra errors after we recover from `const async fn`
 #[doc(hidden)]
 #[unstable(feature = "gen_future", issue = "50547")]
-#[cfg(not(bootstrap))]
 #[inline]
 pub const fn from_generator<T>(gen: T) -> impl Future<Output = T::Return>
 where
@@ -75,7 +70,6 @@ where
 
 #[doc(hidden)]
 #[unstable(feature = "gen_future", issue = "50547")]
-#[cfg(not(bootstrap))]
 #[inline]
 pub unsafe fn get_context<'a, 'b>(cx: ResumeTy) -> &'a mut Context<'b> {
     &mut *cx.0.as_ptr().cast()
diff --git a/src/libcore/intrinsics.rs b/src/libcore/intrinsics.rs
index 75c7313089112..45633dc3ca51f 100644
--- a/src/libcore/intrinsics.rs
+++ b/src/libcore/intrinsics.rs
@@ -980,22 +980,7 @@ extern "rust-intrinsic" {
     ///
     /// The stabilized version of this intrinsic is
     /// [`std::mem::size_of_val`](../../std/mem/fn.size_of_val.html).
-    #[cfg(bootstrap)]
-    pub fn size_of_val<T: ?Sized>(_: &T) -> usize;
-    /// The minimum alignment of the type of the value that `val` points to.
-    ///
-    /// The stabilized version of this intrinsic is
-    /// [`std::mem::min_align_of_val`](../../std/mem/fn.min_align_of_val.html).
-    #[cfg(bootstrap)]
-    pub fn min_align_of_val<T: ?Sized>(_: &T) -> usize;
-
-    /// The size of the referenced value in bytes.
-    ///
-    /// The stabilized version of this intrinsic is
-    /// [`std::mem::size_of_val`](../../std/mem/fn.size_of_val.html).
-    #[cfg(not(bootstrap))]
     pub fn size_of_val<T: ?Sized>(_: *const T) -> usize;
-    #[cfg(not(bootstrap))]
     pub fn min_align_of_val<T: ?Sized>(_: *const T) -> usize;
 
     /// Gets a static string slice containing the name of a type.
@@ -1016,22 +1001,14 @@ extern "rust-intrinsic" {
 
     /// A guard for unsafe functions that cannot ever be executed if `T` is uninhabited:
     /// This will statically either panic, or do nothing.
-    #[cfg(bootstrap)]
-    pub fn panic_if_uninhabited<T>();
-
-    /// A guard for unsafe functions that cannot ever be executed if `T` is uninhabited:
-    /// This will statically either panic, or do nothing.
-    #[cfg(not(bootstrap))]
     pub fn assert_inhabited<T>();
 
     /// A guard for unsafe functions that cannot ever be executed if `T` does not permit
     /// zero-initialization: This will statically either panic, or do nothing.
-    #[cfg(not(bootstrap))]
     pub fn assert_zero_valid<T>();
 
     /// A guard for unsafe functions that cannot ever be executed if `T` has invalid
     /// bit patterns: This will statically either panic, or do nothing.
-    #[cfg(not(bootstrap))]
     pub fn assert_uninit_valid<T>();
 
     /// Gets a reference to a static `Location` indicating where it was called.
@@ -1597,17 +1574,10 @@ extern "rust-intrinsic" {
     /// May assume inputs are finite.
     pub fn frem_fast<T: Copy>(a: T, b: T) -> T;
 
-    /// Convert with LLVM’s fptoui/fptosi, which may return undef for values out of range
-    /// (<https://github.com/rust-lang/rust/issues/10184>)
-    /// This is under stabilization at <https://github.com/rust-lang/rust/issues/67058>
-    #[cfg(bootstrap)]
-    pub fn float_to_int_approx_unchecked<Float: Copy, Int: Copy>(value: Float) -> Int;
-
     /// Convert with LLVM’s fptoui/fptosi, which may return undef for values out of range
     /// (<https://github.com/rust-lang/rust/issues/10184>)
     ///
     /// Stabilized as `f32::to_int_unchecked` and `f64::to_int_unchecked`.
-    #[cfg(not(bootstrap))]
     pub fn float_to_int_unchecked<Float: Copy, Int: Copy>(value: Float) -> Int;
 
     /// Returns the number of bits set in an integer type `T`
@@ -1877,10 +1847,7 @@ extern "rust-intrinsic" {
     /// takes the data pointer and a pointer to the target-specific exception
     /// object that was caught. For more information see the compiler's
     /// source as well as std's catch implementation.
-    #[cfg(not(bootstrap))]
     pub fn r#try(try_fn: fn(*mut u8), data: *mut u8, catch_fn: fn(*mut u8, *mut u8)) -> i32;
-    #[cfg(bootstrap)]
-    pub fn r#try(f: fn(*mut u8), data: *mut u8, local_ptr: *mut u8) -> i32;
 
     /// Emits a `!nontemporal` store according to LLVM (see their docs).
     /// Probably will never become stable.
diff --git a/src/libcore/iter/range.rs b/src/libcore/iter/range.rs
index 37369289c512e..bb68184c8dd77 100644
--- a/src/libcore/iter/range.rs
+++ b/src/libcore/iter/range.rs
@@ -70,7 +70,7 @@ macro_rules! step_identical_methods {
         fn sub_one(&self) -> Self {
             Sub::sub(*self, 1)
         }
-    }
+    };
 }
 
 macro_rules! step_impl_unsigned {
diff --git a/src/libcore/lib.rs b/src/libcore/lib.rs
index 1c7bce3fac583..3b7929f00168a 100644
--- a/src/libcore/lib.rs
+++ b/src/libcore/lib.rs
@@ -99,7 +99,7 @@
 #![feature(lang_items)]
 #![feature(link_llvm_intrinsics)]
 #![feature(llvm_asm)]
-#![cfg_attr(not(bootstrap), feature(negative_impls))]
+#![feature(negative_impls)]
 #![feature(never_type)]
 #![feature(nll)]
 #![feature(exhaustive_patterns)]
diff --git a/src/libcore/macros/mod.rs b/src/libcore/macros/mod.rs
index 73404a73e3d00..85d848f54fbb7 100644
--- a/src/libcore/macros/mod.rs
+++ b/src/libcore/macros/mod.rs
@@ -1,27 +1,3 @@
-#[cfg(bootstrap)]
-#[doc(include = "panic.md")]
-#[macro_export]
-#[allow_internal_unstable(core_panic, track_caller)]
-#[stable(feature = "core", since = "1.6.0")]
-macro_rules! panic {
-    () => (
-        $crate::panic!("explicit panic")
-    );
-    ($msg:expr) => (
-        $crate::panicking::panic($msg)
-    );
-    ($msg:expr,) => (
-        $crate::panic!($msg)
-    );
-    ($fmt:expr, $($arg:tt)+) => (
-        $crate::panicking::panic_fmt(
-            $crate::format_args!($fmt, $($arg)+),
-            $crate::panic::Location::caller(),
-        )
-    );
-}
-
-#[cfg(not(bootstrap))]
 #[doc(include = "panic.md")]
 #[macro_export]
 #[allow_internal_unstable(core_panic, track_caller)]
@@ -1341,25 +1317,6 @@ pub(crate) mod builtin {
     /// Read the [unstable book] for the usage.
     ///
     /// [unstable book]: ../unstable-book/library-features/asm.html
-    #[cfg(bootstrap)]
-    #[unstable(
-        feature = "llvm_asm",
-        issue = "70173",
-        reason = "inline assembly is not stable enough for use and is subject to change"
-    )]
-    #[macro_export]
-    #[allow_internal_unstable(asm)]
-    macro_rules! llvm_asm {
-        // Redirect to asm! for stage0
-        ($($arg:tt)*) => { $crate::asm!($($arg)*) }
-    }
-
-    /// Inline assembly.
-    ///
-    /// Read the [unstable book] for the usage.
-    ///
-    /// [unstable book]: ../unstable-book/library-features/asm.html
-    #[cfg(not(bootstrap))]
     #[unstable(
         feature = "llvm_asm",
         issue = "70173",
@@ -1460,7 +1417,6 @@ pub(crate) mod builtin {
     }
 
     /// Keeps the item it's applied to if the passed path is accessible, and removes it otherwise.
-    #[cfg(not(bootstrap))]
     #[unstable(
         feature = "cfg_accessible",
         issue = "64797",
diff --git a/src/libcore/marker.rs b/src/libcore/marker.rs
index 549933ceeb645..09a8b417e6e22 100644
--- a/src/libcore/marker.rs
+++ b/src/libcore/marker.rs
@@ -90,7 +90,7 @@ impl<T: ?Sized> !Send for *mut T {}
             ch19-04-advanced-types.html#dynamically-sized-types-and-the-sized-trait>"
 )]
 #[fundamental] // for Default, for example, which requires that `[T]: !Default` be evaluatable
-#[cfg_attr(not(bootstrap), rustc_specialization_trait)]
+#[rustc_specialization_trait]
 pub trait Sized {
     // Empty.
 }
diff --git a/src/libcore/mem/maybe_uninit.rs b/src/libcore/mem/maybe_uninit.rs
index bf39d56fc115c..f7ea7eba7b16b 100644
--- a/src/libcore/mem/maybe_uninit.rs
+++ b/src/libcore/mem/maybe_uninit.rs
@@ -495,9 +495,6 @@ impl<T> MaybeUninit<T> {
     #[inline(always)]
     #[rustc_diagnostic_item = "assume_init"]
     pub unsafe fn assume_init(self) -> T {
-        #[cfg(bootstrap)]
-        intrinsics::panic_if_uninhabited::<T>();
-        #[cfg(not(bootstrap))]
         intrinsics::assert_inhabited::<T>();
         ManuallyDrop::into_inner(self.value)
     }
@@ -562,9 +559,6 @@ impl<T> MaybeUninit<T> {
     #[unstable(feature = "maybe_uninit_extra", issue = "63567")]
     #[inline(always)]
     pub unsafe fn read(&self) -> T {
-        #[cfg(bootstrap)]
-        intrinsics::panic_if_uninhabited::<T>();
-        #[cfg(not(bootstrap))]
         intrinsics::assert_inhabited::<T>();
         self.as_ptr().read()
     }
@@ -627,9 +621,6 @@ impl<T> MaybeUninit<T> {
     #[unstable(feature = "maybe_uninit_ref", issue = "63568")]
     #[inline(always)]
     pub unsafe fn get_ref(&self) -> &T {
-        #[cfg(bootstrap)]
-        intrinsics::panic_if_uninhabited::<T>();
-        #[cfg(not(bootstrap))]
         intrinsics::assert_inhabited::<T>();
         &*self.value
     }
@@ -748,9 +739,6 @@ impl<T> MaybeUninit<T> {
     #[unstable(feature = "maybe_uninit_ref", issue = "63568")]
     #[inline(always)]
     pub unsafe fn get_mut(&mut self) -> &mut T {
-        #[cfg(bootstrap)]
-        intrinsics::panic_if_uninhabited::<T>();
-        #[cfg(not(bootstrap))]
         intrinsics::assert_inhabited::<T>();
         &mut *self.value
     }
diff --git a/src/libcore/mem/mod.rs b/src/libcore/mem/mod.rs
index 7fcfbf108144c..b1bbcaeab8def 100644
--- a/src/libcore/mem/mod.rs
+++ b/src/libcore/mem/mod.rs
@@ -378,7 +378,6 @@ pub fn size_of_val<T: ?Sized>(val: &T) -> usize {
 /// assert_eq!(13, unsafe { mem::size_of_val_raw(y) });
 /// ```
 #[inline]
-#[cfg(not(bootstrap))]
 #[unstable(feature = "layout_for_ptr", issue = "69835")]
 pub unsafe fn size_of_val_raw<T: ?Sized>(val: *const T) -> usize {
     intrinsics::size_of_val(val)
@@ -509,7 +508,6 @@ pub fn align_of_val<T: ?Sized>(val: &T) -> usize {
 /// assert_eq!(4, unsafe { mem::align_of_val_raw(&5i32) });
 /// ```
 #[inline]
-#[cfg(not(bootstrap))]
 #[unstable(feature = "layout_for_ptr", issue = "69835")]
 pub unsafe fn align_of_val_raw<T: ?Sized>(val: *const T) -> usize {
     intrinsics::min_align_of_val(val)
@@ -621,10 +619,7 @@ pub const fn needs_drop<T>() -> bool {
 #[allow(deprecated)]
 #[rustc_diagnostic_item = "mem_zeroed"]
 pub unsafe fn zeroed<T>() -> T {
-    #[cfg(not(bootstrap))]
     intrinsics::assert_zero_valid::<T>();
-    #[cfg(bootstrap)]
-    intrinsics::panic_if_uninhabited::<T>();
     MaybeUninit::zeroed().assume_init()
 }
 
@@ -657,10 +652,7 @@ pub unsafe fn zeroed<T>() -> T {
 #[allow(deprecated)]
 #[rustc_diagnostic_item = "mem_uninitialized"]
 pub unsafe fn uninitialized<T>() -> T {
-    #[cfg(not(bootstrap))]
     intrinsics::assert_uninit_valid::<T>();
-    #[cfg(bootstrap)]
-    intrinsics::panic_if_uninhabited::<T>();
     MaybeUninit::uninit().assume_init()
 }
 
diff --git a/src/libcore/ops/deref.rs b/src/libcore/ops/deref.rs
index e2deeb556610c..6e96aa330ff19 100644
--- a/src/libcore/ops/deref.rs
+++ b/src/libcore/ops/deref.rs
@@ -81,7 +81,6 @@ impl<T: ?Sized> Deref for &T {
     }
 }
 
-#[cfg(not(bootstrap))]
 #[stable(feature = "rust1", since = "1.0.0")]
 impl<T: ?Sized> !DerefMut for &T {}
 
diff --git a/src/libcore/ops/index.rs b/src/libcore/ops/index.rs
index 64dd633f75d2b..763b33606fe88 100644
--- a/src/libcore/ops/index.rs
+++ b/src/libcore/ops/index.rs
@@ -65,7 +65,7 @@ pub trait Index<Idx: ?Sized> {
 
     /// Performs the indexing (`container[index]`) operation.
     #[stable(feature = "rust1", since = "1.0.0")]
-    #[cfg_attr(not(bootstrap), track_caller)]
+    #[track_caller]
     fn index(&self, index: Idx) -> &Self::Output;
 }
 
@@ -167,6 +167,6 @@ see chapter in The Book <https://doc.rust-lang.org/book/ch08-02-strings.html#ind
 pub trait IndexMut<Idx: ?Sized>: Index<Idx> {
     /// Performs the mutable indexing (`container[index]`) operation.
     #[stable(feature = "rust1", since = "1.0.0")]
-    #[cfg_attr(not(bootstrap), track_caller)]
+    #[track_caller]
     fn index_mut(&mut self, index: Idx) -> &mut Self::Output;
 }
diff --git a/src/libcore/panicking.rs b/src/libcore/panicking.rs
index 1e4209fd26be3..94ea9b78828db 100644
--- a/src/libcore/panicking.rs
+++ b/src/libcore/panicking.rs
@@ -49,13 +49,9 @@ pub fn panic(expr: &str) -> ! {
     // truncation and padding (even though none is used here). Using
     // Arguments::new_v1 may allow the compiler to omit Formatter::pad from the
     // output binary, saving up to a few kilobytes.
-    #[cfg(not(bootstrap))]
     panic_fmt(fmt::Arguments::new_v1(&[expr], &[]));
-    #[cfg(bootstrap)]
-    panic_fmt(fmt::Arguments::new_v1(&[expr], &[]), Location::caller());
 }
 
-#[cfg(not(bootstrap))]
 #[cold]
 #[cfg_attr(not(feature = "panic_immediate_abort"), inline(never))]
 #[track_caller]
@@ -69,30 +65,12 @@ fn panic_bounds_check(index: usize, len: usize) -> ! {
     panic!("index out of bounds: the len is {} but the index is {}", len, index)
 }
 
-// For bootstrap, we need a variant with the old argument order, and a corresponding
-// `panic_fmt`.
-#[cfg(bootstrap)]
-#[cold]
-#[cfg_attr(not(feature = "panic_immediate_abort"), inline(never))]
-#[lang = "panic_bounds_check"] // needed by codegen for panic on OOB array/slice access
-fn panic_bounds_check(location: &Location<'_>, index: usize, len: usize) -> ! {
-    if cfg!(feature = "panic_immediate_abort") {
-        // SAFETY: the `abort` intrinsic has no requirements to be called.
-        unsafe { super::intrinsics::abort() }
-    }
-
-    panic_fmt(
-        format_args!("index out of bounds: the len is {} but the index is {}", len, index),
-        location,
-    )
-}
-
 /// The underlying implementation of libcore's `panic!` macro when formatting is used.
 #[cold]
 #[cfg_attr(not(feature = "panic_immediate_abort"), inline(never))]
 #[cfg_attr(feature = "panic_immediate_abort", inline)]
-#[cfg_attr(not(bootstrap), track_caller)]
-pub fn panic_fmt(fmt: fmt::Arguments<'_>, #[cfg(bootstrap)] location: &Location<'_>) -> ! {
+#[track_caller]
+pub fn panic_fmt(fmt: fmt::Arguments<'_>) -> ! {
     if cfg!(feature = "panic_immediate_abort") {
         // SAFETY: the `abort` intrinsic has no requirements to be called.
         unsafe { super::intrinsics::abort() }
@@ -105,9 +83,6 @@ pub fn panic_fmt(fmt: fmt::Arguments<'_>, #[cfg(bootstrap)] location: &Location<
         fn panic_impl(pi: &PanicInfo<'_>) -> !;
     }
 
-    #[cfg(bootstrap)]
-    let pi = PanicInfo::internal_constructor(Some(&fmt), location);
-    #[cfg(not(bootstrap))]
     let pi = PanicInfo::internal_constructor(Some(&fmt), Location::caller());
 
     // SAFETY: `panic_impl` is defined in safe Rust code and thus is safe to call.
diff --git a/src/libcore/prelude/v1.rs b/src/libcore/prelude/v1.rs
index 6a51d39ab9d4e..b4fff3d67b555 100644
--- a/src/libcore/prelude/v1.rs
+++ b/src/libcore/prelude/v1.rs
@@ -69,7 +69,6 @@ pub use crate::macros::builtin::{
     bench, global_allocator, test, test_case, RustcDecodable, RustcEncodable,
 };
 
-#[cfg(not(bootstrap))]
 #[unstable(
     feature = "cfg_accessible",
     issue = "64797",
diff --git a/src/libcore/ptr/const_ptr.rs b/src/libcore/ptr/const_ptr.rs
index 729e0b897c098..35a0852bbf545 100644
--- a/src/libcore/ptr/const_ptr.rs
+++ b/src/libcore/ptr/const_ptr.rs
@@ -706,7 +706,6 @@ impl<T: ?Sized> *const T {
     }
 }
 
-#[cfg(not(bootstrap))]
 #[lang = "const_slice_ptr"]
 impl<T> *const [T] {
     /// Returns the length of a raw slice.
diff --git a/src/libcore/ptr/mut_ptr.rs b/src/libcore/ptr/mut_ptr.rs
index 3b7e83bf37fa6..dbd92ce5fcc5b 100644
--- a/src/libcore/ptr/mut_ptr.rs
+++ b/src/libcore/ptr/mut_ptr.rs
@@ -894,7 +894,6 @@ impl<T: ?Sized> *mut T {
     }
 }
 
-#[cfg(not(bootstrap))]
 #[lang = "mut_slice_ptr"]
 impl<T> *mut [T] {
     /// Returns the length of a raw slice.
diff --git a/src/libcore/slice/mod.rs b/src/libcore/slice/mod.rs
index dc395bcfba5cc..7b357bb487a0a 100644
--- a/src/libcore/slice/mod.rs
+++ b/src/libcore/slice/mod.rs
@@ -2831,13 +2831,13 @@ pub trait SliceIndex<T: ?Sized>: private_slice_index::Sealed {
     /// Returns a shared reference to the output at this location, panicking
     /// if out of bounds.
     #[unstable(feature = "slice_index_methods", issue = "none")]
-    #[cfg_attr(not(bootstrap), track_caller)]
+    #[track_caller]
     fn index(self, slice: &T) -> &Self::Output;
 
     /// Returns a mutable reference to the output at this location, panicking
     /// if out of bounds.
     #[unstable(feature = "slice_index_methods", issue = "none")]
-    #[cfg_attr(not(bootstrap), track_caller)]
+    #[track_caller]
     fn index_mut(self, slice: &mut T) -> &mut Self::Output;
 }
 
diff --git a/src/libpanic_abort/lib.rs b/src/libpanic_abort/lib.rs
index f44a875c9d0d5..fd3e11858cef6 100644
--- a/src/libpanic_abort/lib.rs
+++ b/src/libpanic_abort/lib.rs
@@ -106,15 +106,6 @@ pub mod personalities {
         1 // `ExceptionContinueSearch`
     }
 
-    // Similar to above, this corresponds to the `eh_unwind_resume` lang item
-    // that's only used on Windows currently.
-    //
-    // Note that we don't execute landing pads, so this is never called, so it's
-    // body is empty.
-    #[rustc_std_internal_symbol]
-    #[cfg(all(bootstrap, target_os = "windows", target_env = "gnu"))]
-    pub extern "C" fn rust_eh_unwind_resume() {}
-
     // These two are called by our startup objects on i686-pc-windows-gnu, but
     // they don't need to do anything so the bodies are nops.
     #[rustc_std_internal_symbol]
diff --git a/src/libpanic_unwind/gcc.rs b/src/libpanic_unwind/gcc.rs
index 1622442a5eb45..f5d83c21da068 100644
--- a/src/libpanic_unwind/gcc.rs
+++ b/src/libpanic_unwind/gcc.rs
@@ -311,18 +311,6 @@ unsafe fn find_eh_action(
     eh::find_eh_action(lsda, &eh_context, foreign_exception)
 }
 
-#[cfg(all(
-    bootstrap,
-    target_os = "windows",
-    any(target_arch = "x86", target_arch = "x86_64"),
-    target_env = "gnu"
-))]
-#[lang = "eh_unwind_resume"]
-#[unwind(allowed)]
-unsafe extern "C" fn rust_eh_unwind_resume(panic_ctx: *mut u8) -> ! {
-    uw::_Unwind_Resume(panic_ctx as *mut uw::_Unwind_Exception);
-}
-
 // Frame unwind info registration
 //
 // Each module's image contains a frame unwind info section (usually
diff --git a/src/libpanic_unwind/seh.rs b/src/libpanic_unwind/seh.rs
index 9eff37f17663a..8d8276b4159ac 100644
--- a/src/libpanic_unwind/seh.rs
+++ b/src/libpanic_unwind/seh.rs
@@ -213,7 +213,6 @@ extern "C" {
 //
 // This is fine since the MSVC runtime uses string comparison on the type name
 // to match TypeDescriptors rather than pointer equality.
-#[cfg_attr(bootstrap, lang = "eh_catch_typeinfo")]
 static mut TYPE_DESCRIPTOR: _TypeDescriptor = _TypeDescriptor {
     pVFTable: unsafe { &TYPE_INFO_VTABLE } as *const _ as *const _,
     spare: core::ptr::null_mut(),
diff --git a/src/libproc_macro/lib.rs b/src/libproc_macro/lib.rs
index 3cbe852de7b5a..eb7677e9345f2 100644
--- a/src/libproc_macro/lib.rs
+++ b/src/libproc_macro/lib.rs
@@ -24,11 +24,10 @@
 #![feature(decl_macro)]
 #![feature(extern_types)]
 #![feature(in_band_lifetimes)]
-#![cfg_attr(not(bootstrap), feature(negative_impls))]
+#![feature(negative_impls)]
 #![feature(optin_builtin_traits)]
 #![feature(rustc_attrs)]
-#![cfg_attr(bootstrap, feature(specialization))]
-#![cfg_attr(not(bootstrap), feature(min_specialization))]
+#![feature(min_specialization)]
 #![recursion_limit = "256"]
 
 #[unstable(feature = "proc_macro_internals", issue = "27812")]
@@ -274,14 +273,14 @@ impl !Send for Span {}
 impl !Sync for Span {}
 
 macro_rules! diagnostic_method {
-    ($name:ident, $level:expr) => (
+    ($name:ident, $level:expr) => {
         /// Creates a new `Diagnostic` with the given `message` at the span
         /// `self`.
         #[unstable(feature = "proc_macro_diagnostic", issue = "54140")]
         pub fn $name<T: Into<String>>(self, message: T) -> Diagnostic {
             Diagnostic::spanned(self, $level, message)
         }
-    )
+    };
 }
 
 impl Span {
diff --git a/src/librustc_metadata/rmeta/table.rs b/src/librustc_metadata/rmeta/table.rs
index 752caff754eeb..bacb5a345fca9 100644
--- a/src/librustc_metadata/rmeta/table.rs
+++ b/src/librustc_metadata/rmeta/table.rs
@@ -42,10 +42,7 @@ macro_rules! fixed_size_encoding_byte_len_and_defaults {
             // but slicing `[u8]` with `i * N..` is optimized worse, due to the
             // possibility of `i * N` overflowing, than indexing `[[u8; N]]`.
             let b = unsafe {
-                std::slice::from_raw_parts(
-                    b.as_ptr() as *const [u8; BYTE_LEN],
-                    b.len() / BYTE_LEN,
-                )
+                std::slice::from_raw_parts(b.as_ptr() as *const [u8; BYTE_LEN], b.len() / BYTE_LEN)
             };
             b.get(i).map(|b| FixedSizeEncoding::from_bytes(b))
         }
@@ -61,7 +58,7 @@ macro_rules! fixed_size_encoding_byte_len_and_defaults {
             };
             self.write_to_bytes(&mut b[i]);
         }
-    }
+    };
 }
 
 impl FixedSizeEncoding for u32 {
diff --git a/src/librustc_span/lib.rs b/src/librustc_span/lib.rs
index e8252d96350db..060ad604369fb 100644
--- a/src/librustc_span/lib.rs
+++ b/src/librustc_span/lib.rs
@@ -9,7 +9,7 @@
 #![feature(const_if_match)]
 #![feature(const_fn)]
 #![feature(const_panic)]
-#![cfg_attr(not(bootstrap), feature(negative_impls))]
+#![feature(negative_impls)]
 #![feature(nll)]
 #![feature(optin_builtin_traits)]
 #![feature(specialization)]
diff --git a/src/libserialize/json.rs b/src/libserialize/json.rs
index cacc28b6e60e4..7565bdeb4096e 100644
--- a/src/libserialize/json.rs
+++ b/src/libserialize/json.rs
@@ -2305,7 +2305,7 @@ macro_rules! read_primitive {
                 value => Err(ExpectedError("Number".to_owned(), value.to_string())),
             }
         }
-    }
+    };
 }
 
 impl crate::Decoder for Decoder {
diff --git a/src/libstd/ascii.rs b/src/libstd/ascii.rs
index 41bdfea53e559..5cd2a25b11768 100644
--- a/src/libstd/ascii.rs
+++ b/src/libstd/ascii.rs
@@ -149,23 +149,35 @@ pub trait AsciiExt {
 macro_rules! delegating_ascii_methods {
     () => {
         #[inline]
-        fn is_ascii(&self) -> bool { self.is_ascii() }
+        fn is_ascii(&self) -> bool {
+            self.is_ascii()
+        }
 
         #[inline]
-        fn to_ascii_uppercase(&self) -> Self::Owned { self.to_ascii_uppercase() }
+        fn to_ascii_uppercase(&self) -> Self::Owned {
+            self.to_ascii_uppercase()
+        }
 
         #[inline]
-        fn to_ascii_lowercase(&self) -> Self::Owned { self.to_ascii_lowercase() }
+        fn to_ascii_lowercase(&self) -> Self::Owned {
+            self.to_ascii_lowercase()
+        }
 
         #[inline]
-        fn eq_ignore_ascii_case(&self, o: &Self) -> bool { self.eq_ignore_ascii_case(o) }
+        fn eq_ignore_ascii_case(&self, o: &Self) -> bool {
+            self.eq_ignore_ascii_case(o)
+        }
 
         #[inline]
-        fn make_ascii_uppercase(&mut self) { self.make_ascii_uppercase(); }
+        fn make_ascii_uppercase(&mut self) {
+            self.make_ascii_uppercase();
+        }
 
         #[inline]
-        fn make_ascii_lowercase(&mut self) { self.make_ascii_lowercase(); }
-    }
+        fn make_ascii_lowercase(&mut self) {
+            self.make_ascii_lowercase();
+        }
+    };
 }
 
 #[stable(feature = "rust1", since = "1.0.0")]
diff --git a/src/libstd/future.rs b/src/libstd/future.rs
index c0675eeba98da..e2092cfefa369 100644
--- a/src/libstd/future.rs
+++ b/src/libstd/future.rs
@@ -1,111 +1,5 @@
 //! Asynchronous values.
 
-#[cfg(bootstrap)]
-use core::{
-    cell::Cell,
-    marker::Unpin,
-    ops::{Drop, Generator, GeneratorState},
-    pin::Pin,
-    ptr::NonNull,
-    task::{Context, Poll},
-};
-
 #[doc(inline)]
 #[stable(feature = "futures_api", since = "1.36.0")]
 pub use core::future::*;
-
-/// Wrap a generator in a future.
-///
-/// This function returns a `GenFuture` underneath, but hides it in `impl Trait` to give
-/// better error messages (`impl Future` rather than `GenFuture<[closure.....]>`).
-// This is `const` to avoid extra errors after we recover from `const async fn`
-#[cfg(bootstrap)]
-#[doc(hidden)]
-#[unstable(feature = "gen_future", issue = "50547")]
-pub const fn from_generator<T: Generator<Yield = ()>>(x: T) -> impl Future<Output = T::Return> {
-    GenFuture(x)
-}
-
-/// A wrapper around generators used to implement `Future` for `async`/`await` code.
-#[cfg(bootstrap)]
-#[doc(hidden)]
-#[unstable(feature = "gen_future", issue = "50547")]
-#[derive(Copy, Clone, Debug, Eq, PartialEq, Ord, PartialOrd, Hash)]
-struct GenFuture<T: Generator<Yield = ()>>(T);
-
-// We rely on the fact that async/await futures are immovable in order to create
-// self-referential borrows in the underlying generator.
-#[cfg(bootstrap)]
-impl<T: Generator<Yield = ()>> !Unpin for GenFuture<T> {}
-
-#[cfg(bootstrap)]
-#[doc(hidden)]
-#[unstable(feature = "gen_future", issue = "50547")]
-impl<T: Generator<Yield = ()>> Future for GenFuture<T> {
-    type Output = T::Return;
-    fn poll(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
-        // Safe because we're !Unpin + !Drop mapping to a ?Unpin value
-        let gen = unsafe { Pin::map_unchecked_mut(self, |s| &mut s.0) };
-        let _guard = unsafe { set_task_context(cx) };
-        match gen.resume(()) {
-            GeneratorState::Yielded(()) => Poll::Pending,
-            GeneratorState::Complete(x) => Poll::Ready(x),
-        }
-    }
-}
-
-#[cfg(bootstrap)]
-thread_local! {
-    static TLS_CX: Cell<Option<NonNull<Context<'static>>>> = Cell::new(None);
-}
-
-#[cfg(bootstrap)]
-struct SetOnDrop(Option<NonNull<Context<'static>>>);
-
-#[cfg(bootstrap)]
-impl Drop for SetOnDrop {
-    fn drop(&mut self) {
-        TLS_CX.with(|tls_cx| {
-            tls_cx.set(self.0.take());
-        });
-    }
-}
-
-// Safety: the returned guard must drop before `cx` is dropped and before
-// any previous guard is dropped.
-#[cfg(bootstrap)]
-unsafe fn set_task_context(cx: &mut Context<'_>) -> SetOnDrop {
-    // transmute the context's lifetime to 'static so we can store it.
-    let cx = core::mem::transmute::<&mut Context<'_>, &mut Context<'static>>(cx);
-    let old_cx = TLS_CX.with(|tls_cx| tls_cx.replace(Some(NonNull::from(cx))));
-    SetOnDrop(old_cx)
-}
-
-#[cfg(bootstrap)]
-#[doc(hidden)]
-#[unstable(feature = "gen_future", issue = "50547")]
-/// Polls a future in the current thread-local task waker.
-pub fn poll_with_tls_context<F>(f: Pin<&mut F>) -> Poll<F::Output>
-where
-    F: Future,
-{
-    let cx_ptr = TLS_CX.with(|tls_cx| {
-        // Clear the entry so that nested `get_task_waker` calls
-        // will fail or set their own value.
-        tls_cx.replace(None)
-    });
-    let _reset = SetOnDrop(cx_ptr);
-
-    let mut cx_ptr = cx_ptr.expect(
-        "TLS Context not set. This is a rustc bug. \
-        Please file an issue on https://github.com/rust-lang/rust.",
-    );
-
-    // Safety: we've ensured exclusive access to the context by
-    // removing the pointer from TLS, only to be replaced once
-    // we're done with it.
-    //
-    // The pointer that was inserted came from an `&mut Context<'_>`,
-    // so it is safe to treat as mutable.
-    unsafe { F::poll(f, cx_ptr.as_mut()) }
-}
diff --git a/src/libstd/lib.rs b/src/libstd/lib.rs
index 9d2810cacc2bf..5fd15bb8fe4f3 100644
--- a/src/libstd/lib.rs
+++ b/src/libstd/lib.rs
@@ -242,7 +242,7 @@
 #![feature(atomic_mut_ptr)]
 #![feature(box_syntax)]
 #![feature(c_variadic)]
-#![cfg_attr(not(bootstrap), feature(cfg_accessible))]
+#![feature(cfg_accessible)]
 #![feature(cfg_target_has_atomic)]
 #![feature(cfg_target_thread_local)]
 #![feature(char_error_internals)]
@@ -281,7 +281,7 @@
 #![feature(maybe_uninit_ref)]
 #![feature(maybe_uninit_slice)]
 #![feature(needs_panic_runtime)]
-#![cfg_attr(not(bootstrap), feature(negative_impls))]
+#![feature(negative_impls)]
 #![feature(never_type)]
 #![feature(nll)]
 #![feature(optin_builtin_traits)]
@@ -298,8 +298,7 @@
 #![feature(shrink_to)]
 #![feature(slice_concat_ext)]
 #![feature(slice_internals)]
-#![cfg_attr(bootstrap, feature(specialization))]
-#![cfg_attr(not(bootstrap), feature(min_specialization))]
+#![feature(min_specialization)]
 #![feature(staged_api)]
 #![feature(std_internals)]
 #![feature(stdsimd)]
diff --git a/src/libstd/panicking.rs b/src/libstd/panicking.rs
index 10078bd4aee82..343b2ee12735f 100644
--- a/src/libstd/panicking.rs
+++ b/src/libstd/panicking.rs
@@ -271,44 +271,12 @@ pub unsafe fn r#try<R, F: FnOnce() -> R>(f: F) -> Result<R, Box<dyn Any + Send>>
     let mut data = Data { f: ManuallyDrop::new(f) };
 
     let data_ptr = &mut data as *mut _ as *mut u8;
-    return if do_try(do_call::<F, R>, data_ptr, do_catch::<F, R>) == 0 {
+    return if intrinsics::r#try(do_call::<F, R>, data_ptr, do_catch::<F, R>) == 0 {
         Ok(ManuallyDrop::into_inner(data.r))
     } else {
         Err(ManuallyDrop::into_inner(data.p))
     };
 
-    // Compatibility wrapper around the try intrinsic for bootstrap.
-    //
-    // We also need to mark it #[inline(never)] to work around a bug on MinGW
-    // targets: the unwinding implementation was relying on UB, but this only
-    // becomes a problem in practice if inlining is involved.
-    #[cfg(not(bootstrap))]
-    use intrinsics::r#try as do_try;
-    #[cfg(bootstrap)]
-    #[inline(never)]
-    unsafe fn do_try(try_fn: fn(*mut u8), data: *mut u8, catch_fn: fn(*mut u8, *mut u8)) -> i32 {
-        use crate::mem::MaybeUninit;
-        #[cfg(target_env = "msvc")]
-        type TryPayload = [u64; 2];
-        #[cfg(not(target_env = "msvc"))]
-        type TryPayload = *mut u8;
-
-        let mut payload: MaybeUninit<TryPayload> = MaybeUninit::uninit();
-        let payload_ptr = payload.as_mut_ptr() as *mut u8;
-        let r = intrinsics::r#try(try_fn, data, payload_ptr);
-        if r != 0 {
-            #[cfg(target_env = "msvc")]
-            {
-                catch_fn(data, payload_ptr)
-            }
-            #[cfg(not(target_env = "msvc"))]
-            {
-                catch_fn(data, payload.assume_init())
-            }
-        }
-        r
-    }
-
     // We consider unwinding to be rare, so mark this function as cold. However,
     // do not mark it no-inline -- that decision is best to leave to the
     // optimizer (in most cases this function is not inlined even as a normal,
@@ -320,9 +288,7 @@ pub unsafe fn r#try<R, F: FnOnce() -> R>(f: F) -> Result<R, Box<dyn Any + Send>>
         obj
     }
 
-    // See comment on do_try above for why #[inline(never)] is needed on bootstrap.
-    #[cfg_attr(bootstrap, inline(never))]
-    #[cfg_attr(not(bootstrap), inline)]
+    #[inline]
     fn do_call<F: FnOnce() -> R, R>(data: *mut u8) {
         unsafe {
             let data = data as *mut Data<F, R>;
diff --git a/src/libstd/prelude/v1.rs b/src/libstd/prelude/v1.rs
index 92e3ea8485036..0fbd6b62f18ff 100644
--- a/src/libstd/prelude/v1.rs
+++ b/src/libstd/prelude/v1.rs
@@ -54,7 +54,6 @@ pub use core::prelude::v1::{
     PartialEq, PartialOrd, RustcDecodable, RustcEncodable,
 };
 
-#[cfg(not(bootstrap))]
 #[unstable(
     feature = "cfg_accessible",
     issue = "64797",
diff --git a/src/stage0.txt b/src/stage0.txt
index 1c7c9f9aff095..150d7a0943db0 100644
--- a/src/stage0.txt
+++ b/src/stage0.txt
@@ -12,7 +12,7 @@
 # source tarball for a stable release you'll likely see `1.x.0` for rustc and
 # `0.(x+1).0` for Cargo where they were released on `date`.
 
-date: 2020-03-12
+date: 2020-04-22
 rustc: beta
 cargo: beta
 
@@ -20,7 +20,7 @@ cargo: beta
 # bootstrapping issues with use of new syntax in this repo. If you're looking at
 # the beta/stable branch, this key should be omitted, as we don't want to depend
 # on rustfmt from nightly there.
-rustfmt: nightly-2020-01-31
+rustfmt: nightly-2020-04-22
 
 # When making a stable release the process currently looks like:
 #
diff --git a/src/tools/compiletest/src/runtest.rs b/src/tools/compiletest/src/runtest.rs
index 1dd5adb2209ef..b2d477553361a 100644
--- a/src/tools/compiletest/src/runtest.rs
+++ b/src/tools/compiletest/src/runtest.rs
@@ -45,7 +45,7 @@ fn disable_error_reporting<F: FnOnce() -> R, R>(f: F) -> R {
     use winapi::um::winbase::SEM_NOGPFAULTERRORBOX;
 
     lazy_static! {
-        static ref LOCK: Mutex<()> = { Mutex::new(()) };
+        static ref LOCK: Mutex<()> = Mutex::new(());
     }
     // Error mode is a global variable, so lock it so only one thread will change it
     let _lock = LOCK.lock().unwrap();