Add more temp regs, allow swapping if necessary.
Preserve orig regs when applying vfpu prefixes.
Use prefixD directly in jit, just like interp now.
Handle temp regs better, no need for direct access.
Make applying prefixes mostly automatic.

And implement (hopefully) D prefixes.
Support known prefixes in the vfpu jit.
Try to reuse temp regs for better caching.
Merge pull request #729 from unknownbrackets/jit-vfpu

Jit known prefix support