* Because inter-communicators cannot be used with the neighbor alltoall
  exchanger, an alternative needs to be picked in that case.

* This provides for access to class information without needing an
  instance.

* This adds live-patching of a problem in mpi_type_create_(h)indexed
  for MPICH 3.4, 3.4.1, and 3.4.2
* Alternatively, one can build MPICH with the patch from
  config/checkpatch/mpich_3.4_yaksa_hindexed.patch