Bug#25608828: I_MAIN.VARIABLES-BUG21503595 FAILS

              SPORADICALLY ON PB2-5.5 FOR LINUX-VALGRIND

Description: Sporadic failure of variables-bug21503595 test
on pb2-5.5 for linux-valgrind platform.

Fix: This is a issue related to libc and not related to
MySQL code. During dlclose few blocks of memory left
unfreed. This is a known issue in libc and needs to be
suppressed.

Fix: Added a valgrind suppression.

mysql-test/valgrind.supp

-# Copyright (c) 2005, 2015, Oracle and/or its affiliates. All rights reserved.
+# Copyright (c) 2005, 2017, Oracle and/or its affiliates. All rights reserved.
 #
 # This program is free software; you can redistribute it and/or
 # modify it under the terms of the GNU Library General Public
@@ -487,6 +487,15 @@
    fun:dl_open_worker
 }
 
+{
+   libc pthread_exit 9
+   Memcheck:Leak
+   fun:malloc
+   fun:_dl_close_worker
+   fun:_dl_close
+   fun:_dl_catch_error
+}
+
 #
 # This is seen internally in the system libraries on 64-bit RHAS3.
 #