Added test case for MDEV-13029

MDEV 13029 Assertion `ds_control' failed in debug_sync upon closing connection
after creating temporary sequence

This test doesn't fail anymore. Adding it to ensure that the bug doesn't
appear again.

mysql-test/suite/sql_sequence/debug_sync.opt

+--debug-sync-timeout=2

mysql-test/suite/sql_sequence/debug_sync.result

+connect  con1,localhost,root,,;
+CREATE TEMPORARY SEQUENCE f ENGINE=InnoDB;
+disconnect con1;
+connection default;
+SELECT 'Still alive' AS `Heartbeat`;
+Heartbeat
+Still alive

mysql-test/suite/sql_sequence/debug_sync.test

+--source include/have_innodb.inc
+--source include/have_debug_sync.inc
+
+#
+# MDEV-13029
+# Assertion `ds_control' failed in debug_sync upon closing connection after
+# creating temporary sequence
+
+--connect (con1,localhost,root,,)
+CREATE TEMPORARY SEQUENCE f ENGINE=InnoDB;
+--disconnect con1
+--connection default
+--sleep 3
+
+SELECT 'Still alive' AS `Heartbeat`;