This is a partial port of my patch in MySQL 8.0.
In MySQL 8.0, all InnoDB references to DBUG_OFF were replaced
with UNIV_DEBUG. We will not do that in MariaDB.
InnoDB used two independent compile-time flags that distinguish
debug and non-debug builds, which is confusing.
Also, make ut_ad() and alias of DBUG_ASSERT().
innodb_file_format=Barracuda is the default in MariaDB 10.2.
Do not set it, because the option will be removed in MariaDB 10.3.
Also, do not set innodb_file_per_table=1 because it is the default.
Note that MDEV-11828 should fix the test innodb.innodb-64k
already in 10.1.