[llvm] [ConstraintElim] Simplify `sadd_with_overflow` if A and B have different signs (PR #135784)

[Yingwei Zheng via llvm-commits]

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@@ -1673,6 +1674,38 @@ void ConstraintInfo::addFactImpl(CmpInst::Predicate Pred, Value *A, Value *B,
   }
 }
 
+static bool replaceAddOverflowUses(IntrinsicInst *II, Value *A, Value *B,
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dtcxzyw wrote:

We can merge this function with `replaceSubOverflowUses` to avoid duplication.

https://github.com/llvm/llvm-project/pull/135784