[X86] Support SAE for VCVTPS2PH from intrinsic.

[X86] Support SAE for VCVTPS2PH from intrinsic.

For now, clang and gcc both failed to generate sae version from _mm512_cvt_roundps_ph:
https://godbolt.org/z/oh7eTGY5z. Intrinsic guide description is also wrong, which will be
update soon.

Reviewed By: pengfei

Differential Revision: https://reviews.llvm.org/D132641