See https://en.wikipedia.org/wiki/Fowler%E2%80%93Noll%E2%80%93Vo_hash_function#FNV-1_hash.

See https://en.wikipedia.org/wiki/Fowler%E2%80%93Noll%E2%80%93Vo_hash_function#FNV-1a_hash.

fnvHash mixes in data into mix using the ethash fnv method.

hasher is a repetitive hasher allowing the same hash data structures to be reused between hash runs instead of requiring new ones to be created.