add_project_arguments

[dcbaker]

We need support for add_project_arguments.

I see two approaches to this:

1. handle this completely in MIR, by having a transformation pass that walks over all the targets generated and adds these argument to it's argument list
2. handling this in the backend

The first is likely more complicated, though would benefit any future backends.

This is likely going to require the addition of transient state tracking.