interlock. This is applicable in cases where the actual interlock
is the CPU the currently running thread is scheduled on. Borrowing
the scheduler lock as the mutex mandated by pthread_cond_wait()
does away with need to have an additional mutex. This both optimizes
runtime execution and simplifies code, as the extra lock typically
lead to quite some trickeries to avoid the dungeon collapsing due
to zaps from the wand of deadlock.
the source files from src/sys/rump/librump/rumpuser to src/lib/librumpuser
(from where it is already built). Even so, keep rumpuser.h in
sys/rump/include for kernel source tree self-containment.
