[llvm] Fix build by marking possibly unused variable such. (PR #135689)

[via llvm-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-llvm-transforms

Author: None (Sterling-Augustine)

<details>
<summary>Changes</summary>



---
Full diff: https://github.com/llvm/llvm-project/pull/135689.diff


1 Files Affected:

- (modified) llvm/lib/Transforms/Vectorize/VPlanTransforms.cpp (+1-1) 


``````````diff
diff --git a/llvm/lib/Transforms/Vectorize/VPlanTransforms.cpp b/llvm/lib/Transforms/Vectorize/VPlanTransforms.cpp
index b2f495d445686..d0cb1c3ac590f 100644
--- a/llvm/lib/Transforms/Vectorize/VPlanTransforms.cpp
+++ b/llvm/lib/Transforms/Vectorize/VPlanTransforms.cpp
@@ -2414,7 +2414,7 @@ void VPlanTransforms::convertToConcreteRecipes(VPlan &Plan,
         VectorStep = Builder.createWidenCast(CastOp, VectorStep, IVTy);
       }
 
-      auto *ConstStep =
+      [[maybe_unused]] auto *ConstStep =
           ScalarStep->isLiveIn()
               ? dyn_cast<ConstantInt>(ScalarStep->getLiveInIRValue())
               : nullptr;

``````````

</details>


https://github.com/llvm/llvm-project/pull/135689