Bug#27127, Incorrect behaviour of timestamp column with DEFAULT CURRENT_TIMESTAMP correct the bitmap_set_bit when a field is timestamp and described  with default CURRENT_TIMESTAMP or on update CURRENT_TIMESTAMP, then it will reduce a little time cost when the field doesnot need  to write.
Bug#27127, Incorrect behaviour of timestamp column with DEFAULT CURRENT_TIMESTAMP
correct the bitmap_set_bit when a field is timestamp and described 
with default CURRENT_TIMESTAMP or on update CURRENT_TIMESTAMP,
then it will reduce a little time cost when the field doesnot need 
to write.

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