Rollup merge of rust-lang#120143 - compiler-errors:consolidate-instance-resolve-for-coroutines, r=oli-obk

Consolidate logic around resolving built-in coroutine trait impls

Deduplicates a lot of code. Requires defining a new lang item for `Coroutine::resume` for consistency, but it seems not harmful at worst, and potentially later useful at best.

r? oli-obk

Author: matthiaskrgr

core/src/ops/coroutine.rs

@@ -111,6 +111,7 @@ pub trait Coroutine<R = ()> {
     /// been returned previously. While coroutine literals in the language are
     /// guaranteed to panic on resuming after `Complete`, this is not guaranteed
     /// for all implementations of the `Coroutine` trait.
+    #[cfg_attr(not(bootstrap), lang = "coroutine_resume")]
     fn resume(self: Pin<&mut Self>, arg: R) -> CoroutineState<Self::Yield, Self::Return>;
 }