MDEV-4066 semisync_master + temporary tables causes memory leaks

close (and auto-drop) temporary tables before
rolling back the last transaction in the connection.

mysql-test/suite/rpl/r/semisync_memleak_4066.result

+include/master-slave.inc
+[connection master]
+INSTALL PLUGIN rpl_semi_sync_master SONAME 'semisync_master.so';
+CREATE TEMPORARY TABLE tmp (i INT);
+include/rpl_end.inc
+uninstall plugin rpl_semi_sync_master;

mysql-test/suite/rpl/t/semisync_memleak_4066.test

+# 
+# MDEV-4066 semisync_master + temporary tables causes memory leaks
+#
+source include/have_semisync_plugin.inc;
+source include/have_binlog_format_row.inc;
+source include/master-slave.inc;
+
+connection master;
+
+--replace_result .dll .so
+eval INSTALL PLUGIN rpl_semi_sync_master SONAME '$SEMISYNC_MASTER_SO';
+
+--connect (con1,localhost,root,,)
+CREATE TEMPORARY TABLE tmp (i INT);
+--disconnect con1 
+
+source include/rpl_end.inc;
+uninstall plugin rpl_semi_sync_master;
+

sql/sql_class.cc

@@ -1383,11 +1383,12 @@ void THD::cleanup(void)
 #error xid_state in the cache should be replaced by the allocated value
   }
 #endif
-  {
+
+  close_temporary_tables(this);
+
   transaction.xid_state.xa_state= XA_NOTR;
   trans_rollback(this);
   xid_cache_delete(&transaction.xid_state);
-  }
 
   locked_tables_list.unlock_locked_tables(this);
   mysql_ha_cleanup(this);
@@ -1421,7 +1422,6 @@ void THD::cleanup(void)
 
   delete_dynamic(&user_var_events);
   my_hash_free(&user_vars);
-  close_temporary_tables(this);
   sp_cache_clear(&sp_proc_cache);
   sp_cache_clear(&sp_func_cache);