merge FLUSH .. FOR EXPORT

There is an InnoDB-related feature (while not in InnoDB itself), introduced in MySQL 5.6.6, that was missed unintentionally.

InnoDB: InnoDB tables now support the notion of "transportable tablespaces", allowing .ibd files to be exported from a running MySQL instance and imported into another running instance. The FOR EXPORT clause of the FLUSH TABLE command writes any unsaved changes from InnoDB memory buffers to the .ibd file. After copying the .ibd file and a separate metadata file to the other server, you can use the DISCARD TABLESPACE and IMPORT TABLESPACE clauses of the ALTER TABLE statement to bring the table data into a different MySQL instance.

The new FLUSH syntax does not work.