Bug#11755438: Bug#47213: INNODB MUTEX/RW_LOCK SHOULD BE CONSCIOUS ABOUT MEMORY ORDERING OTHER THAN INTEL

Because of difference about memory ordering, some critical flags of mutex/rw_lock might be missed to read on non-Intel CPUs.
Even for Intel-CPUs, the explicit memory barrier instruction might cause positive effects for performance.

Approved by Kevin Lewis in rb#5561