[llvm] [VPlan] Fix header phi VPInstruction verification. NFC (PR #151472)

[David Sherwood via llvm-commits]

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@@ -80,8 +80,8 @@ bool VPlanVerifier::verifyPhiRecipes(const VPBasicBlock *VPBB) {
       NumActiveLaneMaskPhiRecipes++;
 
     if (IsHeaderVPBB && !isa<VPHeaderPHIRecipe, VPWidenPHIRecipe>(*RecipeI) &&
-        !isa<VPInstruction>(*RecipeI) &&
-        cast<VPInstruction>(RecipeI)->getOpcode() == Instruction::PHI) {
+        !(isa<VPInstruction>(*RecipeI) &&
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david-arm wrote:

Looking at the definition of isPhi it seems like we're missing tests where we have a VPPredInstPHIRecipe in the header VPBB, since that seems to be the only one (besides VPInstructions) where isPhi would return true and `isa<VPHeaderPHIRecipe, VPWidenPHIRecipe>(*RecipeI)` would return false.

https://github.com/llvm/llvm-project/pull/151472