[llvm] [VPlan] Add new VPIRPhi overlay for VPIRInsts wrapping phi nodes (NFC). (PR #129387)

[via llvm-commits]

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@@ -1033,16 +1033,19 @@ class VPInstruction : public VPRecipeWithIRFlags,
 class VPIRInstruction : public VPRecipeBase {
   Instruction &I;
 
-public:
+protected:
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ayalz wrote:

Worth documenting that VPIRInstructions should be constructed by calling create() rather than the constructor directly, as a subclass may potentially be created.

https://github.com/llvm/llvm-project/pull/129387