[llvm] [VPlan] Remove manual region removal when simplifying for VF and UF. (PR #181252)

[Luke Lau via llvm-commits]

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@@ -1526,7 +1526,7 @@ static void simplifyRecipe(VPSingleDefRecipe *Def, VPTypeAnalysis &TypeInfo) {
     return;
   }
 
-  if (isa<VPPhi, VPWidenPHIRecipe>(Def)) {
+  if (isa<VPPhi, VPWidenPHIRecipe, VPHeaderPHIRecipe>(Def)) {
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lukel97 wrote:

Just checking this is because removeBranchOnConst only removes the latch incoming value, so we need to simplify the header recipes to the start value?

https://github.com/llvm/llvm-project/pull/181252