support ARM v8 crc32c instructions

[mattbishop]

It looks like ARMv8 has CRC32C instructions available.

https://elixir.bootlin.com/linux/v4.6/source/arch/arm64/crypto/crc32-arm64.c

[mattbishop]

The crc32c crate now supports aarch64: https://github.com/zowens/crc32c/blob/master/src/hw_aarch64.rs

[Brooooooklyn]

Close by #463