Gate AsyncFn* under async_closure feature

Author: compiler-errors

library/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"]