[llvm] [VPlan] Hook IR blocks into VPlan during skeleton creation (NFC) (PR #114292)

[via llvm-commits]

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@@ -1010,8 +1007,9 @@ void VPlan::execute(VPTransformState *State) {
   BasicBlock *VectorPreHeader = State->CFG.PrevBB;
   State->Builder.SetInsertPoint(VectorPreHeader->getTerminator());
 
-  // Disconnect VectorPreHeader from ExitBB in both the CFG and DT.
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ayalz wrote:

Need to disconnect in DT only?
Retain the comment wrt DT?

https://github.com/llvm/llvm-project/pull/114292