llvm-project

cdaeecab - [VPlan] Only remove backedge if IV is still incremented by VFxUF.

[VPlan] Only remove backedge if IV is still incremented by VFxUF. After 6f253e87dd, VFxUF may have been replaced by UF, in which case the simplification is no longer correct. Tighten check to make sure the increment is still what we expect. Fixes a miscompile in the added test case.