liblockdep: Add pthread_mutex_t test suite

This is a rather simple and basic test suite to test common
locking issues.

Beyond tests, it also shows how to use the library.

Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: torvalds@linux-foundation.org
Link: http://lkml.kernel.org/r/1371163284-6346-5-git-send-email-sasha.levin@oracle.com


Signed-off-by: Ingo Molnar <mingo@kernel.org>