It is and it isn't; that is, from a language perspective, the big thing here is type-level integers, which we accepted an RFC for, but is going to take some time to land due to implementation work being tough. It'll get there though!

As for a library ffast-math, it's mostly that we rarely hear people asking for it. I think that many people who want to do numerics stuff are waiting on the above; once it lands, I think more people will start writing libraries. Time will tell!