Fix assert failures in main.merge test (line 234) and main.merge_mmap (line 44) - After the merge from mysql-5.6, open_tables() did not call   open_and_process_table() for temporary table. The logic was that temporary   tables were already opened when mysql_execute_command() has called    open_temporary_tables().   This worked for the most part, except for temporary tables of type MERGE. for   which open_and_process_table() must call      table->file->extra(HA_EXTRA_ADD_CHILDREN_LIST).   Failure to make this call resulted in crash further in execution.
Fix assert failures in main.merge test (line 234) and main.merge_mmap (line 44)
- After the merge from mysql-5.6, open_tables() did not call
  open_and_process_table() for temporary table. The logic was that temporary
  tables were already opened when mysql_execute_command() has called 
  open_temporary_tables().
  This worked for the most part, except for temporary tables of type MERGE. for
  which open_and_process_table() must call 
    table->file->extra(HA_EXTRA_ADD_CHILDREN_LIST).
  Failure to make this call resulted in crash further in execution.

  tables->table->file->extra(HA_EXTRA_ADD_CHILDREN_LIST)
  


natsys/mariadb_10.2,natsys/mariadb_10.2,ollie314/server,flynn1973/mariadb-aix,davidl-zend/zenddbi,ollie314/server,flynn1973/mariadb-aix,natsys/mariadb_10.2,natsys/mariadb_10.2,ollie314/server,ollie314/server,davidl-zend/zenddbi,flynn1973/mariadb-aix,ollie314/server,flynn1973/mariadb-aix,flynn1973/mariadb-aix,natsys/mariadb_10.2,flynn1973/mariadb-aix,davidl-zend/zenddbi,natsys/mariadb_10.2,flynn1973/mariadb-aix,natsys/mariadb_10.2,ollie314/server,davidl-zend/zenddbi,davidl-zend/zenddbi,davidl-zend/zenddbi,flynn1973/mariadb-aix,ollie314/server,davidl-zend/zenddbi,davidl-zend/zenddbi,ollie314/server,ollie314/server,davidl-zend/zenddbi,natsys/mariadb_10.2,natsys/mariadb_10.2,natsys/mariadb_10.2,flynn1973/mariadb-aix,davidl-zend/zenddbi,ollie314/server,flynn1973/mariadb-aix,davidl-zend/zenddbi,flynn1973/mariadb-aix,ollie314/server,natsys/mariadb_10.2