[llvm] [msan] Convert vector shadow to scalar before zext (PR #96722)

[Vitaly Buka via llvm-commits]

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@@ -1283,6 +1283,7 @@ struct MemorySanitizerVisitor : public InstVisitor<MemorySanitizerVisitor> {
     const DataLayout &DL = F.getParent()->getDataLayout();
     const Align OriginAlignment = std::max(kMinOriginAlignment, Alignment);
     TypeSize StoreSize = DL.getTypeStoreSize(Shadow->getType());
+    // ZExt cannot convert between vector and scalar
     Value *ConvertedShadow = convertShadowToScalar(Shadow, IRB);
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vitalybuka wrote:

I don't know why we check isZero on coverted shado
I'd rather expect after that.

But this is not for this patch.

https://github.com/llvm/llvm-project/pull/96722