Revert "Add debug_assert_matches macro."

This reverts commit 0a8e401.

library/core/src/macros/mod.rs

@@ -208,42 +208,6 @@ macro_rules! debug_assert_ne {
     ($($arg:tt)*) => (if $crate::cfg!(debug_assertions) { $crate::assert_ne!($($arg)*); })
 }
 
-/// Asserts that an expression matches any of the given patterns.
-///
-/// Like in a `match` expression, the pattern can be optionally followed by `if`
-/// and a guard expression that has access to names bound by the pattern.
-///
-/// On panic, this macro will print the value of the expression with its
-/// debug representation.
-///
-/// Unlike [`assert_matches!`], `debug_assert_matches!` statements are only
-/// enabled in non optimized builds by default. An optimized build will not
-/// execute `debug_assert_matches!` statements unless `-C debug-assertions` is
-/// passed to the compiler. This makes `debug_assert_matches!` useful for
-/// checks that are too expensive to be present in a release build but may be
-/// helpful during development. The result of expanding `debug_assert_matches!`
-/// is always type checked.
-///
-/// # Examples
-///
-/// ```
-/// #![feature(assert_matches)]
-///
-/// let a = 1u32.checked_add(2);
-/// let b = 1u32.checked_sub(2);
-/// debug_assert_matches!(a, Some(_));
-/// debug_assert_matches!(b, None);
-///
-/// let c = Ok("abc".to_string());
-/// debug_assert_matches!(c, Ok(x) | Err(x) if x.len() < 100);
-/// ```
-#[macro_export]
-#[unstable(feature = "assert_matches", issue = "82775")]
-#[allow_internal_unstable(assert_matches)]
-macro_rules! debug_assert_matches {
-    ($($arg:tt)*) => (if $crate::cfg!(debug_assertions) { $crate::assert_matches!($($arg)*); })
-}
-
 /// Returns whether the given expression matches any of the given patterns.
 ///
 /// Like in a `match` expression, the pattern can be optionally followed by `if`

library/std/src/lib.rs

@@ -556,8 +556,8 @@ pub use std_detect::{
 #[stable(feature = "rust1", since = "1.0.0")]
 #[allow(deprecated, deprecated_in_future)]
 pub use core::{
-    assert_eq, assert_ne, debug_assert, debug_assert_eq, debug_assert_matches, debug_assert_ne,
-    matches, r#try, todo, unimplemented, unreachable, write, writeln,
+    assert_eq, assert_ne, debug_assert, debug_assert_eq, debug_assert_ne, matches, r#try, todo,
+    unimplemented, unreachable, write, writeln,
 };
 
 // Re-export built-in macros defined through libcore.