o break newbus api: add a new argument of type driver_filter_t to
bus_setup_intr()
o add an int return code to all fast handlers
o retire INTR_FAST/IH_FAST
For more info: http://docs.freebsd.org/cgi/getmsg.cgi?fetch=465712+0+current/freebsd-current
Approved by: re (implicit?)