- do NOT tick once per instruction in cpu_loop because in the SMP loops   that does too many ticks.  Instead, let the outer loop update ticks   after each processor has stepped through a few instructions. - use a macro CHECK_MAX_INSTRUCTIONS to stop the cpu_loop early if   max_instr_count reaches zero.  This is only compiled in when the   debugger is off.
- do NOT tick once per instruction in cpu_loop because in the SMP loops
  that does too many ticks.  Instead, let the outer loop update ticks
  after each processor has stepped through a few instructions.
- use a macro CHECK_MAX_INSTRUCTIONS to stop the cpu_loop early if
  max_instr_count reaches zero.  This is only compiled in when the
  debugger is off.

marmolejo/bochs-zet,marmolejo/bochs-zet,marmolejo/bochs-zet,marmolejo/bochs-zet,marmolejo/bochs-zet