Implement MPI-R debugging hooks to support Allinea DDT and Rogue Wave Totalview

[PhilMiller]

Original issue: https://charm.cs.illinois.edu/redmine/issues/1303

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http://mpi-forum.org/docs/mpir-specification-10-11-2010.pdf

If we implement the minimal elements of the MPI-R specification, the common MPI debuggers will be equally capable of attaching themselves to Charm++ applications built on a non-MPI machine layer.

[stwhite91]

We can add ARM DDT to the list of parallel debuggers here

[evan-charmworks]

This page has documents on the MPIR Process Acquisition Interface and MPI Message Queue Interface https://www.mpi-forum.org/docs/