- accumulating all emulation code (including floating-point) in one place
- steal MachFPInterrupt() back from SOFTFLOAT for use only with interrupts
and traps from *real* FPUs
- introducing MachEmulateInst() as a common dispatch point for all
emulated instructions
- cleaning up emulation dispatch in trap()
Also, while we're here, implement MIPS2 LL/SC/SYNC emulation for MIPS1.
Tested on r3k with and without SOFTFLOAT enabled.
cc4037a913