MDEV-16273 innodb.alter_kill fails Unknown storage engine 'InnoDB'

The test is shutting down InnoDB, corrupting a file, and finally
restarting InnoDB. Before the shutdown, the test created the table
and inserted some records. Before MDEV-12288, there would be no access
to the table after server restart, but after MDEV-12288 purge would
reset the transaction identifier after the INSERT, and this would
sometimes happen after the restart.

To make the test deterministic, wait for purge to complete before the
shutdown.

mysql-test/suite/innodb/r/alter_kill.result

@@ -2,10 +2,12 @@
 # Bug#16720368 INNODB CRASHES ON BROKEN #SQL*.IBD FILE AT STARTUP
 #
 SET GLOBAL innodb_file_per_table=1;
+SET GLOBAL innodb_purge_rseg_truncate_frequency=1;
 CREATE TABLE bug16720368_1 (a INT PRIMARY KEY) ENGINE=InnoDB;
 connect  con1,localhost,root;
 CREATE TABLE bug16720368 (a INT PRIMARY KEY, b INT) ENGINE=InnoDB;
 INSERT INTO bug16720368 (a) VALUES (1),(2),(3),(4),(5),(6),(7),(8);
+InnoDB		0 transactions not purged
 connection default;
 # Cleanly shutdown mysqld
 disconnect con1;

mysql-test/suite/innodb/t/alter_kill.test

@@ -27,12 +27,14 @@ call mtr.add_suppression("Plugin 'InnoDB' registration as a STORAGE ENGINE faile
 -- echo #
 
 SET GLOBAL innodb_file_per_table=1;
+SET GLOBAL innodb_purge_rseg_truncate_frequency=1;
 
 CREATE TABLE bug16720368_1 (a INT PRIMARY KEY) ENGINE=InnoDB;
 
 connect (con1,localhost,root);
 CREATE TABLE bug16720368 (a INT PRIMARY KEY, b INT) ENGINE=InnoDB;
 INSERT INTO bug16720368 (a) VALUES (1),(2),(3),(4),(5),(6),(7),(8);
+--source include/wait_all_purged.inc
 
 connection default;