[llvm] [VPlan] Use scalar VPPhi instead of VPWidenPHIRecipe in createPlainCFG. (PR #150847)

[via llvm-commits]

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@@ -8239,7 +8239,7 @@ VPRecipeBase *VPRecipeBuilder::tryToCreateWidenRecipe(VPSingleDefRecipe *R,
   VPRecipeBase *Recipe;
   Instruction *Instr = R->getUnderlyingInstr();
   SmallVector<VPValue *, 4> Operands(R->operands());
-  if (auto *PhiR = dyn_cast<VPWidenPHIRecipe>(R)) {
+  if (auto *PhiR = dyn_cast<VPPhi>(R)) {
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ayalz wrote:

```suggestion
  assert(!isa<VPWidenPHIRecipe>(R) && "Only scalar recipes expected);
  if (auto *PhiR = dyn_cast<VPPhi>(R)) {
```
?

https://github.com/llvm/llvm-project/pull/150847