- Interrupt service routines now take a pointer to
the device's softc, rather than a unit number.
- Interrupt handling code in locore.s condensed. Only
remaining "special" handlers are lev0 (spurious),
lev1 (HIL; don't ask), lev6 (clock), and lev7 (NMI).
Only remaining hard-coded device driver reference in
locore is HIL. (clock doesn't count...)
- "dcafastservice" eliminated. DCA driver has new mechanism
to guarantee prompt interrupt service at any ipl (not
just level 5).
- Interrupt code pulled out of autoconf.c and machdep.c and
placed in new file, isr.c