libgomp: Add comment to clarify last_team usage

libgomp/ChangeLog
2015-07-06  Sebastian Huber  <sebastian.huber@embedded-brains.de>

	* libgomp.h (gomp_thread_pool): Comment last_team field.

From-SVN: r225444

libgomp/ChangeLog

+2015-07-06  Sebastian Huber  <sebastian.huber@embedded-brains.de>
+
+	* libgomp.h (gomp_thread_pool): Comment last_team field.
+
 2015-07-02  Uros Bizjak  <ubizjak@gmail.com>
 
 	* testsuite/libgomp.c++/pr66702-1.C: Require

libgomp/libgomp.h

@@ -458,6 +458,9 @@ struct gomp_thread_pool
   struct gomp_thread **threads;
   unsigned threads_size;
   unsigned threads_used;
+  /* The last team is used for non-nested teams to delay their destruction to
+     make sure all the threads in the team move on to the pool's barrier before
+     the team's barrier is destroyed.  */
   struct gomp_team *last_team;
   /* Number of threads running in this contention group.  */
   unsigned long threads_busy;