[llvm] [InstCombine] Improve `foldDeadPhiWeb` compile time (PR #158057)

[Nikita Popov via llvm-commits]

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@@ -62,15 +62,15 @@ bool InstCombinerImpl::foldDeadPhiWeb(PHINode &PN) {
   Stack.push_back(&PN);
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nikic wrote:

We should also add the initial phi node to the Visited set.

https://github.com/llvm/llvm-project/pull/158057