updating isNegatibleForFree and GetNegatedExpression with fmf for fadd

Summary:  A FMF constraint is added to FADD with unsafe still available as the fallback

Reviewers: spatel, wristow, arsenm, hfinkel

Reviewed By: spatel

Subscribers: wdng

Differential Revision: https://reviews.llvm.org/D48180

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@334753 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed