mysql57: disable TABLE_LIST::derived for now
mysql57: disable TABLE_LIST::derived for now

Because MySQL 5.7 makes TABLE_LIST::derived private.

naoa/mroonga,mroonga/mroonga,yoku0825/mroonga,yoku0825/mroonga,mroonga/mroonga,mroonga/mroonga,naoa/mroonga,naoa/mroonga,mroonga/mroonga,yoku0825/mroonga,naoa/mroonga,naoa/mroonga,yoku0825/mroonga,naoa/mroonga,yoku0825/mroonga,yoku0825/mroonga