[llvm] [InstCombine] Remove dead phi web (PR #108876)

[Yingwei Zheng via llvm-commits]

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@@ -634,6 +634,11 @@ class LLVM_LIBRARY_VISIBILITY InstCombinerImpl final
   Instruction *foldPHIArgZextsIntoPHI(PHINode &PN);
   Instruction *foldPHIArgIntToPtrToPHI(PHINode &PN);
 
+  // If the phi is within a phi web, which is formed by the def-use chain
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dtcxzyw wrote:

```suggestion
  /// If the phi is within a phi web, which is formed by the def-use chain
```
Please use `///` for header comments: https://llvm.org/docs/CodingStandards.html#comment-formatting.


https://github.com/llvm/llvm-project/pull/108876