Refactor 'vectorizeLoop' no functionality change.

This patch merges LoopVectorize of InnerLoopVectorizer and InnerLoopUnroller by adding checks for VF=1. This helps in erasing the Unroller code that is almost identical to the InnerLoopVectorizer code.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@189391 91177308-0d34-0410-b5e6-96231b3b80d8