liblockdep: Add pthread_rwlock_t test suite

A simple test to make sure we handle rwlocks correctly.
Signed-off-by: NSasha Levin <sasha.levin@oracle.com>
Signed-off-by: NPeter Zijlstra <peterz@infradead.org>
Cc: torvalds@linux-foundation.org
Link: http://lkml.kernel.org/r/1371163284-6346-7-git-send-email-sasha.levin@oracle.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

tools/lib/lockdep/tests/WW.c

+#include <liblockdep/rwlock.h>
+
+void main(void)
+{
+	pthread_rwlock_t a, b;
+
+	pthread_rwlock_init(&a, NULL);
+	pthread_rwlock_init(&b, NULL);
+
+	pthread_rwlock_wrlock(&a);
+	pthread_rwlock_rdlock(&b);
+	pthread_rwlock_wrlock(&a);
+}