Add `@nogc` to endian related functions in std.bitmanip
Add `@nogc` to std.digest.sha
Add `@nogc` to std.digest.crc
Add `@nogc` to std.digest.md
Add `@nogc` to std.digest.ripemd
Merge pull request #2451 from sinkuu/digest_nogc

Add `@nogc` to digest algorithms