Bug#43435: LOCK_open does not use MY_MUTEX_INIT_FAST
Bug#43435: LOCK_open does not use MY_MUTEX_INIT_FAST

Initialize LOCK_open as a adapative mutex on platforms where the
PTHREAD_ADAPTIVE_MUTEX_INITIALIZER_NP macro is available. The flag
indicates that a thread should spin (busy wait) for some time on a
locked adaptive mutex before blocking (sleeping). It's intended to
to alleviate performance problems due to LOCK_open being a highly
contended mutex.

sql/mysqld.cc:
  Initialize LOCK_open as a adapative mutex.

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