Ristretto should investigate using the new go builtin hash functions

Moved from GitHub ristretto/163

Posted by nes1983:

The latest version of Go ships with a maphash package that’s meant for exactly ristretto’s kind of use case: https://golang.org/pkg/hash/maphash/. It’s probably worth investigating if it can be used in order to get a speed boost.

DisposaBoy commented :

FWIW: https://github.com/dgraph-io/ristretto/pull/160