[llvm] [VPlan] Add VPPhiAccessors to provide interface for phi recipes (NFC) (PR #129388)

[Florian Hahn via llvm-commits]

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@@ -3694,25 +3720,10 @@ void VPReductionPHIRecipe::print(raw_ostream &O, const Twine &Indent,
 }
 #endif
 
-VPBasicBlock *VPWidenPHIRecipe::getIncomingBlock(unsigned I) {
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fhahn wrote:

This is now providing a specialized definition of `VPPhiAccessors<VPWidenPHIRecipe>::getIncomingBlock`, which is needed to instantiate the template for the type and use the generic `getIncomingBlockForRecipe`

https://github.com/llvm/llvm-project/pull/129388