[llvm] [VPlan] Manage noalias/alias_scope metadata in VPlan. (NFC) (PR #136450)

[via llvm-commits]

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@@ -1198,10 +1200,14 @@ class VPIRMetadata {
 protected:
   VPIRMetadata() {}
   VPIRMetadata(Instruction &I) { getMetadataToPropagate(&I, Metadata); }
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ayalz wrote:

Should another `VPIRMetadata(Instruction &I, LoopVersioning *LVer)` constructor be added, for cases where `I` alone does not suffice to capture all its metadata? Effectively inlining `VPRecipeBuilder::getMetadataToPropagate()` into it. This includes augmenting the metadata propagated from `I` with newly added noalias metadata, so more "create"/compose/construct than "get".

https://github.com/llvm/llvm-project/pull/136450