[llvm] [SeparateConstOffsetFromGEP] Preserve inbounds flag based on ValueTracking and NUW (PR #130617)

[Matt Arsenault via llvm-commits]

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@@ -811,6 +780,30 @@ Value *ConstantOffsetExtractor::removeConstOffset(unsigned ChainIndex) {
   return NewBO;
 }
 
+/// A helper function to check if reassociating through an entry in the user
+/// chain would invalidate the GEP's nuw flag.
+static bool allowsPreservingNUW(User *U) {
+  assert(isa<BinaryOperator>(U) || isa<CastInst>(U) || isa<ConstantInt>(U));
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arsenm wrote:

ConstantInt being a User is a wart, but that doesn't imply that constantInt can use an operator 

https://github.com/llvm/llvm-project/pull/130617