[X86][ABI] Do not return float/double from x87 registers when x87 is disabled

This is aligned with GCC's behavior.
Also, alias `-mno-fp-ret-in-387` to `-mno-x87`, by which we can fix pr51498.

Reviewed By: nickdesaulniers

Differential Revision: https://reviews.llvm.org/D112143

GitOrigin-RevId: a9fba2be35db674971382e38b99a31403444d9bf
2 files changed