[llvm] [VPlan] Replace VPRegionBlock with explicit CFG before execute (NFCI). (PR #117506)

[via llvm-commits]

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@@ -1124,10 +1121,6 @@ void VPInstructionWithType::print(raw_ostream &O, const Twine &Indent,
 
 void VPPhi::execute(VPTransformState &State) {
   State.setDebugLocFrom(getDebugLoc());
-  assert(getParent() ==
-             getParent()->getPlan()->getVectorLoopRegion()->getEntry() &&
-         "VPInstructions with PHI opcodes must be used for header phis only "
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ayalz wrote:

Ah, ok, the assert is essentially still valid, but harder to detect - if VPPhi is in a header or not.

https://github.com/llvm/llvm-project/pull/117506