[clang] [X86][AVX10] Disable m[no-]avx10.1 and switch m[no-]avx10.2 to alias of 512 bit options (PR #124511)

[Phoebe Wang via cfe-commits]

phoebewang wrote:

> I've been playing around and found that `-mavx10.2 -mno-avx10.2-512` enables `avx10.1-512` but `-mavx10.2-512 -mno-avx10.2-512` obviously doesn't. Does it make sense? It happens because when options match, they are eliminated before processing. But this is a problem not related to the PR.

The old behavior is "correct". Using "" because I think it is just an implementation trick. Though the compliance to it is not important, we decide to remove the -256/-512 options after discussed with GCC folks, to further reduce some confusions. We have to keep 10.1 options for a while, because it's risky to switch avx10.1 to alias of avx10.1-512 directly.

Let me know whether you are happy with this solution or not.

https://github.com/llvm/llvm-project/pull/124511