Add tests for our rx_atomic macros to make sure they do what they say
they do (e.g. rx_atomic_inc() adds 1). Also add a simple test running
a bunch of atomic ops in multiple threads, to try to check that the
operations are actually atomic.
Change-Id: I6e776f280eaf547e9862ceed9798d0d43773fa2c
Reviewed-on: https://gerrit.openafs.org/15279
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Cheyenne Wills <cwills@sinenomine.net>
Reviewed-by: Marcio Brito Barbosa <mbarbosa@sinenomine.net>
Reviewed-by: Benjamin Kaduk <kaduk@mit.edu>