Function _mm512_mask_cvtsepi64_epi8
#[target_feature(enable = "avx512f")]
pub fn _mm512_mask_cvtsepi64_epi8(src: __m128i, k: __mmask8, a: __m512i) -> __m128iConvert packed signed 64-bit integers in a to packed 8-bit integers with signed saturation, and store the results in dst using writemask k (elements are copied from src when the corresponding mask bit is not set).