While reading https://github.com/open-mpi/ompi/pull/6469, I realized that there's no `ompi_info` field indicating whether `mpi.h` includes the MPI-1 compat symbols or not. We should probably add this. Should be a trivial thing to add. It might be specific just to v4.0.x, but *maybe* we might want to add it to master (just hard-coded to "no") for continuity into v5.0.x...?