[llvm] [VPlan] Set flags when constructing zexts using VPWidenCastRecipe (PR #164198)

[Luke Lau via llvm-commits]

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@@ -325,6 +325,8 @@ class VPBuilder {
     VPIRFlags Flags;
     if (Opcode == Instruction::Trunc)
       Flags = VPIRFlags::TruncFlagsTy(false, false);
+    else if (Opcode == Instruction::ZExt)
+      Flags = VPIRFlags::NonNegFlagsTy(false);
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lukel97 wrote:

The issue is that it's getting initialized to the wrong flag type, OperationType::Other. We need to explicitly instantiate it with VPIRFlags::NonNegFlagsTy to get OperationType::NonNeg

https://github.com/llvm/llvm-project/pull/164198