Rollup merge of #100604 - dtolnay:okorerr, r=m-ou-se

Remove unstable Result::into_ok_or_err

Pending FCP: rust-lang/rust#82223 (comment)

```@rustbot``` label +waiting-on-fcp

core/src/result.rs

@@ -1776,40 +1776,6 @@ impl<T, E> Result<Result<T, E>, E> {
  }
 }
 
-impl<T> Result<T, T> {
- /// Returns the [`Ok`] value if `self` is `Ok`, and the [`Err`] value if
- /// `self` is `Err`.
- ///
- /// In other words, this function returns the value (the `T`) of a
- /// `Result<T, T>`, regardless of whether or not that result is `Ok` or
- /// `Err`.
- ///
- /// This can be useful in conjunction with APIs such as
- /// [`Atomic*::compare_exchange`], or [`slice::binary_search`], but only in
- /// cases where you don't care if the result was `Ok` or not.
- ///
- /// [`Atomic*::compare_exchange`]: crate::sync::atomic::AtomicBool::compare_exchange
- ///
- /// # Examples
- ///
- /// ```
- /// #![feature(result_into_ok_or_err)]
- /// let ok: Result<u32, u32> = Ok(3);
- /// let err: Result<u32, u32> = Err(4);
- ///
- /// assert_eq!(ok.into_ok_or_err(), 3);
- /// assert_eq!(err.into_ok_or_err(), 4);
- /// ```
- #[inline]
- #[unstable(feature = "result_into_ok_or_err", reason = "newly added", issue = "82223")]
- pub const fn into_ok_or_err(self) -> T {
- match self {
- Ok(v) => v,
- Err(v) => v,
- }
- }
-}
-
 // This is a separate function to reduce the code size of the methods
 #[cfg(not(feature = "panic_immediate_abort"))]
 #[inline(never)]

core/tests/lib.rs

@@ -75,7 +75,6 @@
 #![feature(const_pin)]
 #![feature(never_type)]
 #![feature(unwrap_infallible)]
-#![feature(result_into_ok_or_err)]
 #![feature(pointer_byte_offsets)]
 #![feature(portable_simd)]
 #![feature(ptr_metadata)]

core/tests/result.rs

@@ -95,15 +95,6 @@ fn test_unwrap_or() {
  assert_eq!(ok_err.unwrap_or(50), 50);
 }
 
-#[test]
-fn test_ok_or_err() {
- let ok: Result<isize, isize> = Ok(100);
- let err: Result<isize, isize> = Err(200);
-
- assert_eq!(ok.into_ok_or_err(), 100);
- assert_eq!(err.into_ok_or_err(), 200);
-}
-
 #[test]
 fn test_unwrap_or_else() {
  fn handler(msg: &'static str) -> isize {