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

[Alexey Bataev via llvm-commits]

================
@@ -2969,8 +2963,8 @@ void InnerLoopVectorizer::fixVectorizedLoop(VPTransformState &State) {
   for (Instruction *PI : PredicatedInstructions)
     sinkScalarOperands(&*PI);
 
-  VPRegionBlock *VectorRegion = State.Plan->getVectorLoopRegion();
-  VPBasicBlock *HeaderVPBB = VectorRegion->getEntryBasicBlock();
+  VPBasicBlock *HeaderVPBB = cast<VPBasicBlock>(
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alexey-bataev wrote:

```suggestion
  auto *HeaderVPBB = cast<VPBasicBlock>(
```


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