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

[Alexey Bataev via llvm-commits]

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@@ -425,13 +425,17 @@ void VPBasicBlock::connectToPredecessors(VPTransformState::CFGState &CFG) {
     VPBasicBlock *PredVPBB = PredVPBlock->getExitingBasicBlock();
     auto &PredVPSuccessors = PredVPBB->getHierarchicalSuccessors();
     BasicBlock *PredBB = CFG.VPBB2IRBB[PredVPBB];
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alexey-bataev wrote:

This kind of accessing may create nullptr entry in `CFG.VPBB2IRBB`. Is this ok?

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