More work on C stub generation.
Add interface for ml_stubs module.
Printer for generated ML stubs.
Generate function for retrieving primitive constructor names.
WIP
Look up the directories for subproject dependencies; don't compute them.
Fix intnat pointer issue in test library.
Generate wrapper functions for ml stubs.

Pass projected raw pointers to C.
Omit trivial wrappers during stub generation.
Order names of native/byte functions in external declaration.
Disable 'noalloc' for the moment.

We need an interface for specifying interaction with callbacks.
Narrow the C_stubs interface.
Generate byte code stub, passing arguments using argc/argv.
Packing and unpacking of structures and unions.
Struct passing (WIP).
Give views an identity.
Give structured types an identity.
More work on view stub generation.
Extend registry to structured types.
Stub generation tests.