prom_lock vs. LOCKDEBUG

[Tobias Nygren <tnn%NetBSD.org@localhost>]

(ignore the duplicate mail if it does appear, accidentally sent from work account and think it got rejected)

Hi all,

It seems LOCKDEBUG has been broken on alpha ever since prom_lock was
converted to kmutex, and the kernel hangs before copyright.
I think the prom stuff is accessed too early in the boot to be able to
use kmutex when LOCKDEBUG is enabled. I recall sparc64 had a similar
problem a while back.
Should we switch to __cpu_simple_lock or is there a better way to
fix this?

(as a quick test, commenting out the prom_lock does get me to
multiuser)

Kind regards,
-Tobias