As part of MDEV-26779 we first discovered the effect of enabling spinning for
some critical mutex. MDEV-26779 tried enabling it for lock_sys.wait_mutex and
observed a good gain in performance.

In yet another discussion, Mark Callaghan pointed a reference to pthread based
mutex spin using PTHREAD_MUTEX_ADAPTIVE_NP (MDEV-26769 Intel RTM).

Given the strong references, Marko Makela as part of his comment in #1923
pointed an idea to enable spinning for other mutexes. Based on perf profiling
we decided to explore spinning for log_sys_mutex and log_flush_order_mutex as
they are occupying the top slots in the contented mutex list.

The evaluation showed promising results for ARM64 but not for x86.
So a patch is here-by proposed to enable the spinning of the mutex for
ARM64-based platform.