Rollup merge of rust-lang#128120 - compiler-errors:async-fn-name, r=oli-obk

Gate `AsyncFn*` under `async_closure` feature

T-lang has not come to a consensus on the naming of async closure callable bounds, and as part of allowing the async closures RFC merge, we agreed to place `AsyncFn` under the same gate as `async Fn` so that these syntaxes can be evaluated in parallel.

See rust-lang/rfcs#3668 (comment)

r? oli-obk

Author: matthiaskrgr

alloc/src/lib.rs

@@ -101,6 +101,7 @@
 #![feature(array_windows)]
 #![feature(ascii_char)]
 #![feature(assert_matches)]
+#![feature(async_closure)]
 #![feature(async_fn_traits)]
 #![feature(async_iterator)]
 #![feature(clone_to_uninit)]

core/src/ops/async_function.rs

@@ -4,7 +4,7 @@ use crate::marker::Tuple;
 /// An async-aware version of the [`Fn`](crate::ops::Fn) trait.
 ///
 /// All `async fn` and functions returning futures implement this trait.
-#[unstable(feature = "async_fn_traits", issue = "none")]
+#[unstable(feature = "async_closure", issue = "62290")]
 #[rustc_paren_sugar]
 #[fundamental]
 #[must_use = "async closures are lazy and do nothing unless called"]
@@ -18,7 +18,7 @@ pub trait AsyncFn<Args: Tuple>: AsyncFnMut<Args> {
 /// An async-aware version of the [`FnMut`](crate::ops::FnMut) trait.
 ///
 /// All `async fn` and functions returning futures implement this trait.
-#[unstable(feature = "async_fn_traits", issue = "none")]
+#[unstable(feature = "async_closure", issue = "62290")]
 #[rustc_paren_sugar]
 #[fundamental]
 #[must_use = "async closures are lazy and do nothing unless called"]
@@ -39,7 +39,7 @@ pub trait AsyncFnMut<Args: Tuple>: AsyncFnOnce<Args> {
 /// An async-aware version of the [`FnOnce`](crate::ops::FnOnce) trait.
 ///
 /// All `async fn` and functions returning futures implement this trait.
-#[unstable(feature = "async_fn_traits", issue = "none")]
+#[unstable(feature = "async_closure", issue = "62290")]
 #[rustc_paren_sugar]
 #[fundamental]
 #[must_use = "async closures are lazy and do nothing unless called"]