ck_rwlock: Add publish semantics for rwlock.

include/ck_rwlock.h

@@ -59,6 +59,7 @@ ck_rwlock_write_lock(ck_rwlock_t *rw)
 	while (ck_pr_load_uint(&rw->n_readers) != 0)
 		ck_pr_stall();
 
+	ck_pr_fence_store();
 	return;
 }
 
@@ -66,6 +67,7 @@ CK_CC_INLINE static void
 ck_rwlock_write_unlock(ck_rwlock_t *rw)
 {
 
+	ck_pr_fence_store();
 	ck_pr_store_uint(&rw->writer, false);
 	return;
 }
@@ -84,6 +86,7 @@ ck_rwlock_read_lock(ck_rwlock_t *rw)
 		ck_pr_dec_uint(&rw->n_readers);
 	}
 
+	ck_pr_fence_load();
 	return;
 }
 
@@ -91,6 +94,7 @@ CK_CC_INLINE static void
 ck_rwlock_read_unlock(ck_rwlock_t *rw)
 {
 
+	ck_pr_fence_load();
 	ck_pr_dec_uint(&rw->n_readers);
 	return;
 }