[x86, AVX] allow FP vector select folding to bitwise logic ops (PR28895)

This handles the case in:
https://llvm.org/bugs/show_bug.cgi?id=28895

...but we are not getting all of the possibilities yet. 
Eg, we use 'X86::FANDN' for scalar FP select combines.

That enhancement is filed as:
https://llvm.org/bugs/show_bug.cgi?id=28925

Differential Revision: https://reviews.llvm.org/D23337

llvm-svn: 278270