[llvm] [VPlan] Allow VPWidenPHI in non-native path and copy DebugLoc (PR #118662)

[Luke Lau via llvm-commits]

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@@ -2285,10 +2285,16 @@ class VPWidenPHIRecipe : public VPSingleDefRecipe {
   /// List of incoming blocks. Only used in the VPlan native path.
   SmallVector<VPBasicBlock *, 2> IncomingBlocks;
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lukel97 wrote:

IncomingBlocks should still only be used in the vplan native path, so I've added more comments to the other methods that should only be called from it

https://github.com/llvm/llvm-project/pull/118662