[llvm] [Coroutines] fix coroutines + std::unique_ptr with async exceptions validation errors (PR #149691)

[Weibo He via llvm-commits]

================
@@ -2229,6 +2325,8 @@ PreservedAnalyses CoroSplitPass::run(LazyCallGraph::SCC &C,
     if (!Shape.CoroBegin)
       continue;
 
+    enforceDominationByCoroBegin(F, Shape);
----------------
NewSigma wrote:

We can simply use:
```C++
if (Shape.ABI == coro::ABI::Switch)
  enforceDominationByCoroBegin(F, Shape);
```

https://github.com/llvm/llvm-project/pull/149691