[llvm] [InstCombine] Extend `foldICmpBinOp` to `add`-like `or`. (PR #71396)

[Mikhail Gudim via llvm-commits]

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@@ -4564,6 +4564,17 @@ static Instruction *foldICmpXorXX(ICmpInst &I, const SimplifyQuery &Q,
   return nullptr;
 }
 
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mgudim wrote:

I have seen checks for `or` which is actually an `add` in other places. Should we make this into a centralized utility function?

https://github.com/llvm/llvm-project/pull/71396