- Use db_printf() instead of printf().
- Clean up decode_syscall() to use regular if-then-else rather than goto's.
- Use the same method of parsing PID's for per-process traces as the x86
code does: that is, if the address passed in is not a valid kernel
address, treat it is a decimal pid.
- If the pid of the current process is specified, fall back to using the
"default" parameters for the trace as curproc's pcb is not valid at this
point.
MFC after: 1 week
fc8bd4c1c0