[llvm] [VPlan] Manage instruction medata in VPlan. (PR #135272)

[via llvm-commits]

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@@ -1204,6 +1204,14 @@ void VPIRPhi::print(raw_ostream &O, const Twine &Indent,
 }
 #endif
 
+void VPWithIRMetadata::setMetadata(Value *V) const {
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ayalz wrote:

Better have the caller dyn_cast to Instruction (and realize metadata may be lost for non Instruction Values) than pretend this can set metadata to any Value?

https://github.com/llvm/llvm-project/pull/135272