if the break instruction is still there. This works around a problem with
the software single step in DDB not recognizing the temporary breakpoint
set to emulate the single step.
undone by rev 1.7:
>redo pmax/include/reg.h
>so that the definitions needed by locore.S are in a separate file,
>pmax/include/regnum.h.
* Add explicit `#include <mips/regnum.h>' where symbolic offsets
into a mips trapframe or struct reg are used..
Add DDB interface to /sys/arch/mips/mips..
Rework heuristic stack traceback to work with DDB.
Add hooks to print exception log from DDB.
Add hooks from pmax console drivers: call Debugger()
after break from serial console, or 'DO' key from LK-xxx.
