Unrolled build for #156936

Rollup merge of #156936 - Darksonn:no-PinCoerceUnsized-for-UnsafePinned, r=Mark-Simulacrum

Remove FIXME about impl PinCoerceUnsized for UnsafePinned<T>

The `PinCoerceUnsized` trait may only be implemented for smart pointer types, but `UnsafePinned` has no indirection. Thus, it will not be correct to add this impl.

Follow-up to #137043

cc @Sky9x

Author: rust-timer

library/core/src/pin/unsafe_pinned.rs

@@ -178,5 +178,3 @@ impl<T: CoerceUnsized<U>, U> CoerceUnsized<UnsafePinned<U>> for UnsafePinned<T>
 #[unstable(feature = "dispatch_from_dyn", issue = "none")]
 // #[unstable(feature = "unsafe_pinned", issue = "125735")]
 impl<T: DispatchFromDyn<U>, U> DispatchFromDyn<UnsafePinned<U>> for UnsafePinned<T> {}
-
-// FIXME(unsafe_pinned): impl PinCoerceUnsized for UnsafePinned<T>?