[llvm] [IVDesc] Use SCEVPatternMatch to improve code (NFC) (PR #168397)

[Florian Hahn via llvm-commits]

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@@ -401,7 +401,7 @@ class InductionDescriptor {
   InductionKind getKind() const { return IK; }
   const SCEV *getStep() const { return Step; }
   BinaryOperator *getInductionBinOp() const { return InductionBinOp; }
-  LLVM_ABI ConstantInt *getConstIntStepValue() const;
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fhahn wrote:

could keep the original name, as it still returns a constant (AP)int?

https://github.com/llvm/llvm-project/pull/168397