Summary:
This change allows lambdas to be used in the RPC dispatching functions.
Just requires an extra function trait to convert a lambda with no
captures into a function pointer. Also rearranged where the `Port` lives
because it looks better no that we may use a lambda and it's more
consistent with the dispatch usage (putting the client at the start).
Summary:
The RPC interface is useful for forwarding functions. This PR adds
helper functions for doing a completely bare forwarding of a function
from the client to the server. This is intended to facilitate
heterogenous libraries that implement host functions on the GPU (like
MPI or Fortran).
