[x86] translating "fp" (floating point) instructions from {fadd,fdiv,fmul,fsub,fsubr...

[x86] translating "fp" (floating point) instructions from {fadd,fdiv,fmul,fsub,fsubr,fdivr} to {faddp,fdivp,fmulp,fsubp,fsubrp,fdivrp}

LLVM Missing the following instructions: fadd\fdiv\fmul\fsub\fsubr\fdivr.
GAS and MS supporting this instruction and lowering them in to a faddp\fdivp\fmulp\fsubp\fsubrp\fdivrp instructions.

Differential Revision: http://reviews.llvm.org/D14217

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@252908 91177308-0d34-0410-b5e6-96231b3b80d8