[llvm] [VPlan] Connect Entry to scalar preheader during initial construction. (PR #140132)

[via llvm-commits]

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@@ -540,6 +540,9 @@ void VPlanTransforms::prepareForVectorization(
     if (auto *LatchExitVPB = MiddleVPBB->getSingleSuccessor())
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ayalz wrote:

Independent: worth clarifying that not requiring a scalar epilog check means the scalar epilog is (always) required, i.e., case 1.

https://github.com/llvm/llvm-project/pull/140132