This adds the AVX512BITALG intrinsics.
It also patches the verification against the Intel Intrinsic Guide
because Rust uses a different naming.
Added intrinsics match _mm(256|512)?(_maskz?)?_popcnt_epi(8|16) for the popcount ones
and _mm(256|512)?(_mask)?_bitshuffle_epi64_mask
This commit partially reverts #868 to restore the intrinsics to their
original implementation to avoid breaking changes. This is done while
rust-lang/rust#73166 is running through crater, and should unblock
rust-lang/rust#74482.
* Update Intel intrinsics definitions with the latest version
* Update _mm256_extract_epi{8,16} to match latest definition
* Fix _mm_extract_epi16 sign extension
Fixes#867
