Function miri::shims::unix::sync::release_cond_mutex_and_block

fn release_cond_mutex_and_block<'mir, 'tcx: 'mir>(
    ecx: &mut MiriInterpCx<'mir, 'tcx>,
    active_thread: ThreadId,
    mutex: MutexId
) -> InterpResult<'tcx>

Release the mutex associated with the condition variable because we are entering the waiting state.