Fix some links in the standard library

Author: petrochenkov

library/core/src/macros/mod.rs

@@ -640,6 +640,8 @@ macro_rules! unreachable {
 ///
 /// Like `panic!`, this macro has a second form for displaying custom values.
 ///
+/// [`todo!`]: crate::todo
+///
 /// # Examples
 ///
 /// Say we have a trait `Foo`:

library/std/src/macros.rs

@@ -31,6 +31,8 @@ macro_rules! panic {
 /// [`eprint!`] instead to print error and progress messages.
 ///
 /// [flush]: crate::io::Write::flush
+/// [`println!`]: crate::println
+/// [`eprint!`]: crate::eprint
 ///
 /// # Panics
 ///
@@ -77,6 +79,7 @@ macro_rules! print {
 /// [`eprintln!`] instead to print error and progress messages.
 ///
 /// [`std::fmt`]: crate::fmt
+/// [`eprintln!`]: crate::eprintln
 ///
 /// # Panics
 ///
@@ -146,6 +149,7 @@ macro_rules! eprint {
 ///
 /// [`io::stderr`]: crate::io::stderr
 /// [`io::stdout`]: crate::io::stdout
+/// [`println!`]: crate::println
 ///
 /// # Panics
 ///

library/std/src/thread/local.rs

@@ -21,6 +21,8 @@ use crate::fmt;
 /// The [`with`] method yields a reference to the contained value which cannot be
 /// sent across threads or escape the given closure.
 ///
+/// [`thread_local!`]: crate::thread_local
+///
 /// # Initialization and Destruction
 ///
 /// Initialization is dynamically performed on the first call to [`with`]

library/std/src/thread/mod.rs

@@ -146,6 +146,7 @@
 //! [`Cell`]: crate::cell::Cell
 //! [`RefCell`]: crate::cell::RefCell
 //! [`with`]: LocalKey::with
+//! [`thread_local!`]: crate::thread_local
 
 #![stable(feature = "rust1", since = "1.0.0")]
 #![deny(unsafe_op_in_unsafe_fn)]