Would you like to add more error handling for return values from functions like the following? - [pthread_cond_wait](http://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_cond_wait.html) ⇒ [Barrier::Wait](https://github.com/google/ion/blob/9e659416fb04bb3d3a67df1e018d7c2ccab9d468/ion/port/barrier.cc#L174) - [pthread_mutex_init](http://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_mutex_init.html) ⇒ [Mutex constructor](https://github.com/google/ion/blob/9e659416fb04bb3d3a67df1e018d7c2ccab9d468/ion/port/mutex.cc#L53)
Would you like to add more error handling for return values from functions like the following?