Function _mm512_mask_mullo_epi64
#[target_feature(enable = "avx512dq")]
pub const fn _mm512_mask_mullo_epi64(src: __m512i, k: __mmask8, a: __m512i, b: __m512i) -> __m512iMultiply packed 64-bit integers in a and b, producing intermediate 128-bit integers, and store
the low 64 bits of the intermediate integers in dst using writemask k (elements are copied from
src if the corresponding bit is not set).