This function is defined in OpenMP-TR6 section 4.1.5.1.6
The functions was not implemented yet.
Since ompt-functions can only be called after the runtime was initialized and has loaded a tool, it can assume the runtime to be initialized. In contrast to omp_get_num_procs which needs to check whether the runtime is initialized.
Maybe check that these two return the same result as for omp{,t}_get_num_places?