Use individual funcs, skipping the ExecuteOpInternal switch

This helps on x86, but I'm having trouble on ARM - it's just not consistent numbers enough, and I can't do it properly with headless.  It'd be good if someone else could verify the performance on Android.

The numbers aren't entirely consistent on x86.  I got better than 1% in a couple places, but when I retry them they sometimes aren't as much faster... anyway, it's 1% better in several places.

-[Unknown]