MyRocks upstream has I_S.table_statistics.ROW_LOCK*, should we import?

The upstream has introduced information_schema.table_statistics.row_lock_deadlocks column (as far as I understand it works for any storage engine, they also have it for InnoDB).

They are also using it in mysql-test/include/deadlock_stats.inc, which is used in rocksdb.deadlocks_stats.

For now, I will just comment out the part of the testcase. In the future we should decide whether to

• Keep not having this feature
• Port it completely
• Replace it with something else (why can't RocksDB export a plugin-specific table with deadlock stats).