Improved crash recovery performance.

Fixed MySQL Bug #52102: InnoDB Plugin shows performance drop comparing to builtin InnoDB on Windows only. Disabled Windows atomics by default.

Fixed MySQL Bug #51378: Init 'ref_length' to correct value, in case of an out of bound MySQL primary_key.

Made SHOW ENGINE INNODB MUTEX STATUS display SUM(os_waits) for the buffer pool block mutexes and locks.

Fixed ALTER TABLE ... IMPORT TABLESPACE of compressed tables.

Fixed MySQL Bug #49535: Available memory check slows down crash recovery tens of times.

Let the master thread sleep if the amount of work to be done is calibrated as taking less than a second.

Fixed MySQL Bug #49001: SHOW INNODB STATUS deadlock info incorrect when deadlock detection aborts.

Fixed MySQL Bug #35077: Very slow DROP TABLE (ALTER TABLE, OPTIMIZE TABLE) on compressed tables.

Fixed MySQL Bug #49497: Error 1467 (ER_AUTOINC_READ_FAILED) on inserting a negative value.

Do not merge buffered inserts to compressed pages before the redo log has been applied in crash recovery.

Do not attempt to access a clustered index record that has been marked for deletion, On the READ UNCOMMITTED isolation level. In previous versions, the InnoDB would attempt to retrieve a previous version of the record in this case.

Fixed an uninitialized access to block->is_hashed, when disabling the adaptive hash index.

Fixed MySQL Bug #46193: Crash when accessing tables after enabling innodb_force_recovery option.

Fixed MySQL Bug #49238: Creating / Dropping a temporary table while at 1023 transactions will cause assert.

Display the zlib version number at startup.