Rollup merge of #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

compiler/rustc_span/src/symbol.rs

@@ -600,6 +600,7 @@ symbols! {
         core_panic_macro,
         coroutine,
         coroutine_clone,
+        coroutine_resume,
         coroutine_state,
         coroutines,
         cosf32,