Rollup merge of #118311 - bvanjoi:merge_coroutinue_into_closure, r=petrochenkov

merge `DefKind::Coroutine` into `Defkind::Closure`

Related to #118188

We no longer need to be concerned about the precise type whether it's `DefKind::Closure` or `DefKind::Coroutine`.

Furthermore, thanks for the great work done by `@petrochenkov` on investigating https://rust-lang.zulipchat.com/#narrow/stream/182449-t-compiler.2Fhelp/topic/Why.20does.20it.20hang.20when.20querying.20.EF.BB.BF.60opt_def_kind.60.3F

r? `@petrochenkov`

compiler/rustc_privacy/src/lib.rs

@@ -653,8 +653,7 @@ impl<'tcx> EmbargoVisitor<'tcx> {
             | DefKind::Field
             | DefKind::GlobalAsm
             | DefKind::Impl { .. }
-            | DefKind::Closure
-            | DefKind::Coroutine => (),
+            | DefKind::Closure => (),
         }
     }
 }