This is a backport of commit 4489a89c
in order to remove the test innodb.redo_log_during_checkpoint
that would cause trouble in the DBUG subsystem invoked by
safe_mutex_lock() via log_checkpoint(). Before
commit 7cffb5f6
these mutexes were of different type.

The following options were introduced in
commit 2e814d47 (mariadb-10.2.2)
and have little use:

innodb_disable_resize_buffer_pool_debug had no effect even in
MariaDB 10.2.2 or MySQL 5.7.9. It was introduced in
mysql/mysql-server@5c4094cf4971eebab89da4ee4ae92c71f69cd524
to work around a problem that was fixed in
mysql/mysql-server@2957ae4f990bf3aed25822b0ce15d3ccad0b54b6
(but the parameter was not removed).

innodb_page_cleaner_disabled_debug and innodb_master_thread_disabled_debug
are only used by the test innodb.redo_log_during_checkpoint
that will be removed as part of this commit.

innodb_dict_stats_disabled_debug is only used by that test,
and it is redundant because one could simply use
innodb_stats_persistent=OFF or the STATS_PERSISTENT=0 attribute
of the table in the test to achieve the same effect.