[llvm] [VPlan] Model middle block via VPIRBasicBlock. (PR #95816)

[Florian Hahn via llvm-commits]

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@@ -851,6 +863,9 @@ void VPlan::execute(VPTransformState *State) {
   State->CFG.ExitBB = State->CFG.PrevBB->getSingleSuccessor();
   BasicBlock *VectorPreHeader = State->CFG.PrevBB;
   State->Builder.SetInsertPoint(VectorPreHeader->getTerminator());
+  replaceVPBBWithIRVPBB(
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fhahn wrote:

Left at the current position as it re-uses `State->CFG.ExitBB` which is set just above

https://github.com/llvm/llvm-project/pull/95816