Rollup merge of #105915 - andrewpollack:revert-105250-async-rm-resume…

…ty, r=tmandry

Revert "Replace usage of `ResumeTy` in async lowering with `Context`"

Reverts rust-lang/rust#105250
Fixes: #105501

Following instructions from [forge](https://forge.rust-lang.org/compiler/reviews.html#reverts).

This change introduced a breaking change that is not actionable nor relevant, and is blocking updates to our toolchain. Along with other comments on the CL marking issues that are fixed by reverts, reverting is best until these issues can be resolved

cc. `@Swatinem`

core/src/future/mod.rs

@@ -44,7 +44,7 @@ pub use poll_fn::{poll_fn, PollFn};
 ///    non-Send/Sync as well, and we don't want that.
 ///
 /// It also simplifies the HIR lowering of `.await`.
-// FIXME(swatinem): This type can be removed when bumping the bootstrap compiler
+#[cfg_attr(not(bootstrap), lang = "ResumeTy")]
 #[doc(hidden)]
 #[unstable(feature = "gen_future", issue = "50547")]
 #[derive(Debug, Copy, Clone)]
@@ -61,7 +61,6 @@ unsafe impl Sync for ResumeTy {}
 /// This function returns a `GenFuture` underneath, but hides it in `impl Trait` to give
 /// better error messages (`impl Future` rather than `GenFuture<[closure.....]>`).
 // This is `const` to avoid extra errors after we recover from `const async fn`
-// FIXME(swatinem): This fn can be removed when bumping the bootstrap compiler
 #[cfg_attr(bootstrap, lang = "from_generator")]
 #[doc(hidden)]
 #[unstable(feature = "gen_future", issue = "50547")]
@@ -103,8 +102,7 @@ where
     GenFuture(gen)
 }
 
-// FIXME(swatinem): This fn can be removed when bumping the bootstrap compiler
-#[cfg_attr(bootstrap, lang = "get_context")]
+#[lang = "get_context"]
 #[doc(hidden)]
 #[unstable(feature = "gen_future", issue = "50547")]
 #[must_use]
@@ -115,10 +113,6 @@ pub unsafe fn get_context<'a, 'b>(cx: ResumeTy) -> &'a mut Context<'b> {
     unsafe { &mut *cx.0.as_ptr().cast() }
 }
 
-// FIXME(swatinem): This fn is currently needed to work around shortcomings
-// in type and lifetime inference.
-// See the comment at the bottom of `LoweringContext::make_async_expr` and
-// <https://github.com/rust-lang/rust/issues/104826>.
 #[cfg_attr(not(bootstrap), lang = "identity_future")]
 #[doc(hidden)]
 #[unstable(feature = "gen_future", issue = "50547")]

core/src/task/wake.rs

@@ -174,7 +174,6 @@ impl RawWakerVTable {
 /// Currently, `Context` only serves to provide access to a [`&Waker`](Waker)
 /// which can be used to wake the current task.
 #[stable(feature = "futures_api", since = "1.36.0")]
-#[cfg_attr(not(bootstrap), lang = "Context")]
 pub struct Context<'a> {
     waker: &'a Waker,
     // Ensure we future-proof against variance changes by forcing