cc @tobiasgrosser @wsmoses
this PR adds some new ops and types to the MLIR MPI dialect. the goal is
to get the minimum required ops here to get a project of us working, and
if everything works well, continue adding ops to the mpi dialect on
subsequent PRs until we achieve some level of compliance with the MPI
standard.
---
Things left to do in subsequent PRs:
- Add back the `mpi.comm` type and add as optional argument of current
implemented ops that should support it (i.e. `send`, `recv`, `isend`,
`irecv`, `allreduce`, `barrier`).
- Support defining custom `MPI_Op`s (the MPI operations, not the
tablegen `MPI_Op`) as regions.
- Add more ops.
48f88651a0