Rollup merge of #70112 - Centril:rollup-gpi5tbq, r=Centril

Rollup of 10 pull requests

Successful merges:

 - #67749 (keyword docs for else and inkeyword docs for else and in.)
 - #69139 (clean up E0308 explanation)
 - #69189 (Erase regions in writeback)
 - #69837 (Use smaller discriminants for generators)
 - #69838 (Expansion-driven outline module parsing)
 - #69839 (Miri error reform)
 - #69899 (Make methods declared by `newtype_index` macro `const`)
 - #69920 (Remove some imports to the rustc crate)
 - #70075 (Fix repr pretty display)
 - #70106 (Tidy: fix running rustfmt twice)

Failed merges:

 - #70051 (Allow `hir().find` to return `None`)
 - #70074 (Expand: nix all fatal errors)

r? @ghost

Author: pietroalbini

Cargo.lock

@@ -3624,6 +3624,7 @@ dependencies = [
  "rustc_data_structures",
  "rustc_hir",
  "rustc_metadata",
+ "rustc_session",
  "rustc_span",
  "rustc_target",
 ]
@@ -3677,6 +3678,7 @@ dependencies = [
  "rustc_parse",
  "rustc_plugin_impl",
  "rustc_save_analysis",
+ "rustc_session",
  "rustc_span",
  "rustc_target",
  "serialize",
@@ -3791,6 +3793,7 @@ dependencies = [
  "rustc_hir",
  "rustc_index",
  "rustc_macros",
+ "rustc_session",
  "rustc_span",
  "rustc_target",
  "smallvec 1.0.0",
@@ -3903,6 +3906,7 @@ dependencies = [
  "rustc_expand",
  "rustc_hir",
  "rustc_index",
+ "rustc_session",
  "rustc_span",
  "rustc_target",
  "serialize",
@@ -3933,6 +3937,7 @@ dependencies = [
  "rustc_infer",
  "rustc_lexer",
  "rustc_macros",
+ "rustc_session",
  "rustc_span",
  "rustc_target",
  "rustc_trait_selection",
@@ -4013,6 +4018,7 @@ dependencies = [
  "rustc_hir",
  "rustc_lint",
  "rustc_metadata",
+ "rustc_session",
  "rustc_span",
 ]
 
@@ -4027,6 +4033,7 @@ dependencies = [
  "rustc_data_structures",
  "rustc_errors",
  "rustc_hir",
+ "rustc_session",
  "rustc_span",
  "rustc_typeck",
 ]
@@ -4068,6 +4075,7 @@ dependencies = [
  "rustc_data_structures",
  "rustc_hir",
  "rustc_parse",
+ "rustc_session",
  "rustc_span",
  "serde_json",
 ]
@@ -4174,6 +4182,7 @@ dependencies = [
  "rustc_data_structures",
  "rustc_hir",
  "rustc_infer",
+ "rustc_session",
  "rustc_span",
  "rustc_target",
  "rustc_trait_selection",
@@ -4193,6 +4202,7 @@ dependencies = [
  "rustc_hir",
  "rustc_index",
  "rustc_infer",
+ "rustc_session",
  "rustc_span",
  "rustc_target",
  "rustc_trait_selection",

src/bootstrap/format.rs

@@ -37,6 +37,9 @@ struct RustfmtConfig {
 }
 
 pub fn format(build: &Build, check: bool) {
+    if build.config.dry_run {
+        return;
+    }
     let mut builder = ignore::types::TypesBuilder::new();
     builder.add_defaults();
     builder.select("rust");

src/libpanic_unwind/emcc.rs

@@ -6,8 +6,6 @@
 //! Emscripten's runtime always implements those APIs and does not
 //! implement libunwind.
 
-#![allow(private_no_mangle_fns)]
-
 use alloc::boxed::Box;
 use core::any::Any;
 use core::mem;

src/libpanic_unwind/gcc.rs

@@ -36,8 +36,6 @@
 //! Once stack has been unwound down to the handler frame level, unwinding stops
 //! and the last personality routine transfers control to the catch block.
 
-#![allow(private_no_mangle_fns)]
-
 use alloc::boxed::Box;
 use core::any::Any;
 

src/libpanic_unwind/seh.rs

@@ -45,7 +45,6 @@
 //! [llvm]: http://llvm.org/docs/ExceptionHandling.html#background-on-windows-exceptions
 
 #![allow(nonstandard_style)]
-#![allow(private_no_mangle_fns)]
 
 use alloc::boxed::Box;
 use core::any::Any;

src/librustc/hir/map/mod.rs

@@ -346,7 +346,7 @@ impl<'hir> Map<'hir> {
     }
 
     fn get_entry(&self, id: HirId) -> Entry<'hir> {
-        if id.local_id == ItemLocalId::from_u32_const(0) {
+        if id.local_id == ItemLocalId::from_u32(0) {
             let owner = self.tcx.hir_owner(id.owner_def_id());
             Entry { parent: owner.parent, node: owner.node }
         } else {

src/librustc/ich/hcx.rs

@@ -1,8 +1,6 @@
-use crate::hir::map::definitions::Definitions;
-use crate::hir::map::DefPathHash;
+use crate::hir::map::definitions::{DefPathHash, Definitions};
 use crate::ich::{self, CachingSourceMapView};
 use crate::middle::cstore::CrateStore;
-use crate::session::Session;
 use crate::ty::{fast_reject, TyCtxt};
 
 use rustc_ast::ast;
@@ -11,6 +9,7 @@ use rustc_data_structures::stable_hasher::{HashStable, StableHasher};
 use rustc_data_structures::sync::Lrc;
 use rustc_hir as hir;
 use rustc_hir::def_id::{DefId, DefIndex};
+use rustc_session::Session;
 use rustc_span::source_map::SourceMap;
 use rustc_span::symbol::Symbol;
 use rustc_span::{BytePos, SourceFile};

src/librustc/lib.rs

@@ -26,6 +26,9 @@
 #![feature(bool_to_option)]
 #![feature(box_patterns)]
 #![feature(box_syntax)]
+#![feature(const_if_match)]
+#![feature(const_fn)]
+#![feature(const_panic)]
 #![feature(const_transmute)]
 #![feature(core_intrinsics)]
 #![feature(drain_filter)]
@@ -80,7 +83,6 @@ pub mod infer;
 pub mod lint;
 pub mod middle;
 pub mod mir;
-pub use rustc_session as session;
 pub mod traits;
 pub mod ty;
 

src/librustc/lint.rs

@@ -5,7 +5,7 @@ use rustc_data_structures::fx::FxHashMap;
 use rustc_data_structures::stable_hasher::{HashStable, StableHasher};
 use rustc_errors::{pluralize, Applicability, DiagnosticBuilder, DiagnosticId};
 use rustc_hir::HirId;
-pub use rustc_session::lint::{builtin, Level, Lint, LintId, LintPass};
+use rustc_session::lint::{builtin, Level, Lint, LintId};
 use rustc_session::{DiagnosticMessageId, Session};
 use rustc_span::hygiene::MacroKind;
 use rustc_span::source_map::{DesugaringKind, ExpnKind, MultiSpan};

src/librustc/middle/cstore.rs

@@ -2,10 +2,9 @@
 //! are *mostly* used as a part of that interface, but these should
 //! probably get a better home if someone can find one.
 
-use crate::hir::map as hir_map;
-use crate::hir::map::definitions::{DefKey, DefPathTable};
-use crate::session::search_paths::PathKind;
-use crate::session::CrateDisambiguator;
+pub use self::NativeLibraryKind::*;
+
+use crate::hir::map::definitions::{DefKey, DefPath, DefPathHash, DefPathTable};
 use crate::ty::TyCtxt;
 
 use rustc_ast::ast;
@@ -14,15 +13,16 @@ use rustc_data_structures::svh::Svh;
 use rustc_data_structures::sync::{self, MetadataRef};
 use rustc_hir::def_id::{CrateNum, DefId, LOCAL_CRATE};
 use rustc_macros::HashStable;
+use rustc_session::search_paths::PathKind;
+pub use rustc_session::utils::NativeLibraryKind;
+use rustc_session::CrateDisambiguator;
 use rustc_span::symbol::Symbol;
 use rustc_span::Span;
 use rustc_target::spec::Target;
+
 use std::any::Any;
 use std::path::{Path, PathBuf};
 
-pub use self::NativeLibraryKind::*;
-pub use rustc_session::utils::NativeLibraryKind;
-
 // lonely orphan structs and enums looking for a better home
 
 /// Where a crate came from on the local filesystem. One of these three options
@@ -197,8 +197,8 @@ pub trait CrateStore {
 
     // resolve
     fn def_key(&self, def: DefId) -> DefKey;
-    fn def_path(&self, def: DefId) -> hir_map::DefPath;
-    fn def_path_hash(&self, def: DefId) -> hir_map::DefPathHash;
+    fn def_path(&self, def: DefId) -> DefPath;
+    fn def_path_hash(&self, def: DefId) -> DefPathHash;
     fn def_path_table(&self, cnum: CrateNum) -> &DefPathTable;
 
     // "queries" used in resolve that aren't tracked for incremental compilation