On AIX, include <sys/atomic_op.h> so that the functions we use for

TAS support are properly declared.

src/include/storage/s_lock.h

@@ -66,7 +66,7 @@
  * Portions Copyright (c) 1996-2007, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- *	  $PostgreSQL: pgsql/src/include/storage/s_lock.h,v 1.159 2007/05/04 15:20:52 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/include/storage/s_lock.h,v 1.160 2007/07/16 02:03:14 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -750,6 +750,8 @@ typedef abilock_t slock_t;
  */
 #define HAS_TEST_AND_SET
 
+#include <sys/atomic_op.h>
+
 typedef unsigned int slock_t;
 
 #define TAS(lock)			_check_lock(lock, 0, 1)