A NoHashHasher<T> where T is one of
{u8, u16, u32, u64, usize, i8, i16, i32, i64, isize}
is a stateless implementation of Hasher which does not actually hash at all.
By itself this hasher is largely useless, but when used in HashMaps whose domain
matches T the resulting map operations involving hashing are faster than
with any other possible hashing algorithm.