[llvm] Reapply "[coro][CoroSplit] Use `llvm.lifetime.end` to compute putting objects on the frame vs the stack (#90265) (PR #91372)

[Nikita Popov via llvm-commits]

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@@ -155,20 +162,31 @@ bool llvm::isPotentiallyReachableFromMany(
     }
   }
 
-  const Loop *StopLoop = LI ? getOutermostLoop(LI, StopBB) : nullptr;
+  SmallPtrSet<const Loop *, 2> StopLoops;
+
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nikic wrote:

Nit: Drop this empty line.

https://github.com/llvm/llvm-project/pull/91372