Added a function scalarizePHI() that sclarizes a vector phi instruction if it has only 2 uses: one to promote the vector phi in a loop and the other use is an extract operation of one element at a constant location.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@179783 91177308-0d34-0410-b5e6-96231b3b80d8