[clang] [clang][CodeGen] Promote point of GRO(CWG2563) (PR #151067)

[Chuanqi Xu via cfe-commits]

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@@ -950,15 +1035,20 @@ void CodeGenFunction::EmitCoroutineBody(const CoroutineBodyStmt &S) {
       // We don't need FinalBB. Emit it to make sure the block is deleted.
       EmitBlock(FinalBB, /*IsFinished=*/true);
     }
+
+    // GRO conversion is unnecessary when get_return_object's type matches the
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ChuanqiXu9 wrote:

nit: we need conversion if get_return_object's type doesn't matches the coroutine return type.

https://github.com/llvm/llvm-project/pull/151067