How to make a robust mutex on AIx [7.1]

Question

Lets assume 2 threads belonging to 2 separate processes share the same mutex object. If thread A holding the lock to the mutex suddenly dies; how would thread B be able to recover the mutex and obtain the lock. I know that on other platforms you can declare the mutex as robust [pthread_mutexattr_setrobust] and then use the [pthread_mutex_consistent] to recover the mutex. but these functions are not available on AIX 7.1