[x86] fold fand (fxor X, -1) Y --> fandn X, Y

I noticed this gap in the scalar FP-logic matching with:
D26712
and:
rL287171

Differential Revision: https://reviews.llvm.org/D27385


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@288675 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed