Clean up code pointer naming for the jit.

Now it properly identifies thunk code which is actually a decent percent
when fastmem is off at least.
Increase the min size of an "interesting" func.

Seeing a bunch of forwarders and stuff that won't hash safely.
Replacements: use memmove, avoid invalid addr.

If size = 0, don't care about addresses.  Some games use 0, 0, 0 and
expect it to work just fine, which it should.
Logging tweak.
Merge pull request #4882 from unknownbrackets/jit-minor

Fix memcpy/memmove replacements, minor tweaks