Function _mm256_bitshuffle_epi64_mask
#[target_feature(enable = "avx512bitalg", enable = "avx512vl")]
pub fn _mm256_bitshuffle_epi64_mask(b: __m256i, c: __m256i) -> __mmask32Considers the input b as packed 64-bit integers and c as packed 8-bit integers.
Then groups 8 8-bit values from cas indices into the bits of the corresponding 64-bit integer.
It then selects these bits and packs them into the output.