[llvm] [VPlan] Make CanIV part of region. (PR #144803)

[via llvm-commits]

================
@@ -1058,7 +1090,12 @@ void VPlan::execute(VPTransformState *State) {
       // Move the last step to the end of the latch block. This ensures
       // consistent placement of all induction updates.
       Instruction *Inc = cast<Instruction>(Phi->getIncomingValue(1));
-      Inc->moveBefore(std::prev(VectorLatchBB->getTerminator()->getIterator()));
+      if (VectorLatchBB->getTerminator()->getIterator() !=
----------------
ayalz wrote:

nit:
```suggestion
      auto *LatchTermIter = VectorLatchBB->getTerminator()->getIterator();
      if (LatchTermIter == VectorLatchBB->begin())
        Inc->moveBefore(LatchTermIter);
      else
        Inc->moveBefore(std::prev(LatchTermIter));     
```

https://github.com/llvm/llvm-project/pull/144803