[llvm] [VPlan] Add new VPInstruction ocpode for header mask. (PR #89603)

[via llvm-commits]

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@@ -132,6 +132,7 @@ bool VPRecipeBase::mayHaveSideEffects() const {
     case VPInstruction::CalculateTripCountMinusVF:
     case VPInstruction::CanonicalIVIncrementForPart:
     case VPInstruction::PtrAdd:
+    case VPInstruction::HeaderMask:
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ayalz wrote:

nit: would be good to list in lex order, so better placed before PtrAdd.

https://github.com/llvm/llvm-project/pull/89603