Fix an issue where fast math flags were dropped during scalarization.

Most portions of InstCombine properly propagate fast math flags, but
apparently the vector scalarization section was overlooked.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@262376 91177308-0d34-0410-b5e6-96231b3b80d8
3 files changed