Try to load inline matrices a bit faster

I've always seen games specify a matrix number, and then the data.  I don't recall ever seeing anything else.

This code just looks ahead at a number call, and loads the matrix data right away.  If there is none, it does nothing, and it still avoids flushing if the data is unchanged.  Mainly, this avoids jumping around between functions and some time in fastrunloop.

It seems a bit messier than I'd like (possibly because I'm tired), and it will prevent a breakpoint on the matrix data from working (this is the case for the existing fast bone matrix loads, too.)

In Gods Eater Burst, this improves performance:
 * By maybe ~0.7% with software skinning enabled, from ~857% to ~863% (or so...)
 * By around ~2% with software skinning disabled, from ~902% to ~922%.

I didn't test it heavily with other games.

-[Unknown]