[llvm] [X86][MC] Added support for -msse2avx option in llvm-mc (PR #96860)

[Shengchen Kan via llvm-commits]

KanRobert wrote:

> > It's binutils flag https://godbolt.org/z/o9MM9br95. GCC only forwards it to AS.
> 
> If it's simply forward, why inline asm is not affected?

It only works when input file is .s, e.g

gcc -c -msse2avx 1.s

https://github.com/llvm/llvm-project/pull/96860