[LV] Factor the creation of the loop induction variable out of createEmptyLoop()

It makes things easier to understand if this is in a helper method. This is part of my ongoing spaghetti-removal operation on createEmptyLoop.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@246632 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed