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

[via llvm-commits]

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@@ -2511,13 +2531,14 @@ void InnerLoopVectorizer::emitIterationCountCheck(BasicBlock *Bypass) {
          "TC check is expected to dominate Bypass");
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ayalz wrote:

This assert was probably added along with the lines below, but should remain, right?

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