Jit breakpoints (x86 only)

I wanted to mess with the jit a bit just because it's interesting.  If these changes aren't good I won't feel bad at all if you don't pull them.

This adds breakpoints for jit, which work reasonably well except around branches.  Even so, it can make debugging easier and more straight-forward.  It's only for x86, and should have minimal impact on perf since it's compile time.

I also made it clear cache as you suggested.  But there were fixups I wasn't too sure about, so I left it at clearing all cache.  Also, I don't clear while running since I assume that would be bad...

We probably need a flag for whether the jit is currently running or not, what do you think?  That would fix some crashes when you exit while the game is running in jit, and a possible crash here if you don't wait long enough.

Also, since the comments said inlining broke some things, I added optimize pragmas around those funcs.  But I'm not sure what compiler it breaks in.

-[Unknown]