long. This is used to check for interrupts being disabled at the time
of a lock() call, if enabled in config.h. The number of times this
happens is then counted in the kinfo structure. These events (recursive
lockings) lead to nasty race conditions.
when lock timing is enabled in minix/config.h.
Added phys_zero() routine to klib386.s that zeroes a range of memory, and
added corresponding system call.
