[clang] [llvm] Revert "[X86][AVX10.2] Support YMM rounding new instructions (#101825)" (PR #132362)

[Phoebe Wang via llvm-commits]

phoebewang wrote:

> LGTM - do we have to remove avx10-256 as well (and just use prefer vector width) or will that remain in some form?

Yes, we will remove avx10-256 and evex512 finally.

https://github.com/llvm/llvm-project/pull/132362