We will default to MUTEXTYPE=sys (using OSTrackMutex) for those
ib_mutex_t that have not been replaced yet.

The view INFORMATION_SCHEMA.INNODB_SYS_SEMAPHORE_WAITS is removed.

The parameter innodb_sync_array_size is removed.

FIXME: innodb_fatal_semaphore_wait_threshold will no longer be enforced.
We should enforce it for lock_sys.mutex and dict_sys.mutex somehow!

innodb_sync_debug=ON might still cover ib_mutex_t.