Support for experimental avx512 operations #35
Description
An avx512-accellerated SIMD implementation should be possible; see e.g. this AWS PR https://github.com/awslabs/aws-checksums/pull/72/files#diff-c767a7149f121bc42a24cecd4428f9b9a2a9f2d4c3a169fbed187605b9de5a26
These functions are still experimental in Rust (rust-lang/rust#111137), but could be used only under this crate's nightly feature gate.