emulation in db_run.c:
- re-arrange `db_*_single_step()' and `db_*_temp_breakpoint()' -
which are only used in the `SOFTWARE_SSTEP' case - so these
are available to the KGDB code.
- make other code in db_run.c conditional on `DDB'.
is no hardware support for single-stepping):
- Fix branch prediction and delay slot computation (for the MIPS).
- Correctly deal with branch taken vs. branch not taken cases, and
self-branches.
- General cleanup, including types botches.
Partially from Mach 3, with a bunch of cleanup work by me.
pk