Specifically:

Revert "MDEV-29664 Assertion `!n_mysql_tables_in_use' failed in innobase_close_connection"
This reverts commit ba875e93.

Revert "MDEV-29620 Assertion `next_insert_id == 0' failed in handler::ha_external_lock"
This reverts commit aa08a744.

Revert "MDEV-29628 Memory leak after CREATE OR REPLACE with foreign key"
This reverts commit c579d66b.

Revert "MDEV-29609 create_not_windows test fails with different result"
This reverts commit cb583b2f.

Revert "MDEV-29544 SIGSEGV in HA_CREATE_INFO::finalize_locked_tables"
This reverts commit dcd66c38.

Revert "MDEV-28933 CREATE OR REPLACE fails to recreate same constraint name"
This reverts commit cf6c5176.

Revert "MDEV-28933 Moved RENAME_CONSTRAINT_IDS to include/sql_funcs.h"
This reverts commit f1e1c133.

Revert "MDEV-28956 Locking is broken if CREATE OR REPLACE fails under LOCK TABLES"
This reverts commit a228ec80.

Revert "MDEV-25292 gcol.gcol_bugfixes --ps fix"
This reverts commit 24fff826.

Revert "MDEV-25292 Disable atomic replace for slave-generated or-replace"
This reverts commit 2af15914.

Revert "MDEV-25292 backup_log improved"
This reverts commit 34398a20.

Revert "MDEV-25292 Atomic CREATE OR REPLACE TABLE"
This reverts commit 93c8252f.

Revert "MDEV-25292 Table_name class for (db, table_name, alias)"
This reverts commit d145dda9.

Revert "MDEV-25292 ha_table_exists() cleanup and improvement"
This reverts commit 409b8a86.

Revert "MDEV-25292 Cleanups"
This reverts commit 595dad83.

Revert "MDEV-25292 Refactoring: moved select_field_count into Alter_info."
This reverts commit f02af1d2.