Rollup merge of rust-lang#130518 - scottmcm:stabilize-controlflow-ext…

…ra, r=dtolnay

Stabilize the `map`/`value` methods on `ControlFlow`

And fix the stability attribute on the `pub use` in `core::ops`.

libs-api in rust-lang#75744 (comment) seemed reasonably happy with naming for these, so let's try for an FCP.

Summary:
```rust
impl<B, C> ControlFlow<B, C> {
    pub fn break_value(self) -> Option<B>;
    pub fn map_break<T>(self, f: impl FnOnce(B) -> T) -> ControlFlow<T, C>;
    pub fn continue_value(self) -> Option<C>;
    pub fn map_continue<T>(self, f: impl FnOnce(C) -> T) -> ControlFlow<B, T>;
}
```

Resolves rust-lang#75744

``@rustbot`` label +needs-fcp +t-libs-api -t-libs

---

Aside, in case it keeps someone else from going down the same dead end: I looked at the `{break,continue}_value` methods and tried to make them `const` as part of this, but that's disallowed because of not having `const Drop`, so put it back to not even unstably-const.

clippy_lints/src/lib.rs

@@ -1,7 +1,6 @@
 #![feature(array_windows)]
 #![feature(binary_heap_into_iter_sorted)]
 #![feature(box_patterns)]
-#![feature(control_flow_enum)]
 #![feature(f128)]
 #![feature(f16)]
 #![feature(if_let_guard)]

clippy_utils/src/lib.rs

@@ -1,6 +1,5 @@
 #![feature(array_chunks)]
 #![feature(box_patterns)]
-#![feature(control_flow_enum)]
 #![feature(f128)]
 #![feature(f16)]
 #![feature(if_let_guard)]