Auto merge of #139114 - m-ou-se:super-let-pin, r=davidtwco

Implement `pin!()` using `super let`

Tracking issue for super let: https://github.com/rust-lang/rust/issues/139076

This uses `super let` to implement `pin!()`.

This means we can remove [the hack](https://github.com/rust-lang/rust/pull/138717) we had to put in to fix https://github.com/rust-lang/rust/issues/138596.

It also means we can remove the original hack to make `pin!()` work, which used a questionable public-but-unstable field rather than a proper private field.

While `super let` is still unstable and subject to change, it seems safe to assume that future Rust will always have a way to express `pin!()` in a compatible way, considering `pin!()` is already stable.

It'd help [the experiment](https://github.com/rust-lang/rust/issues/139076) to have `pin!()` use `super let`, so we can get some more experience with it.

1 files changed, 0 insertions, 1 deletions

diff --git a/compiler/rustc_span/src/symbol.rs b/compiler/rustc_span/src/symbol.rs
index ac7efaffefb..f7b10d3c529 100644
--- a/compiler/rustc_span/src/symbol.rs
+++ b/compiler/rustc_span/src/symbol.rs
@@ -2217,7 +2217,6 @@ symbols! {
         unsafe_extern_blocks,
         unsafe_fields,
         unsafe_no_drop_flag,
-        unsafe_pin_internals,
         unsafe_pinned,
         unsafe_unpin,
         unsize,