[llvm] [clang] [coroutine] Implement llvm.coro.await.suspend intrinsic (PR #79712)

[Chuanqi Xu via cfe-commits]

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@@ -5036,14 +5036,17 @@ class CoroutineSuspendExpr : public Expr {
 
   Stmt *SubExprs[SubExpr::Count];
   OpaqueValueExpr *OpaqueValue = nullptr;
+  OpaqueValueExpr *OpaqueFramePtr = nullptr;
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ChuanqiXu9 wrote:

I still think we can get rid of storing `OpaqueFramePtr` in `CoroutineSuspendExpr`. For example, we can call ` @llvm.coro.frame()` directly to get it. 

https://llvm.org/docs/Coroutines.html#llvm-coro-frame-intrinsic

https://github.com/llvm/llvm-project/pull/79712