Compatibility layer to bridge Interpreter and build.rs functionality

[Shfty]

• Need some sort of interface that unifies I / O
  • Params and return value in the case of functions
  • Initial context writes and final read in the case of Interpreter
• Likely able to implement some trait on a known type in the generated module, use that to dispatch to the precompiled field function

[Shfty]

DONE: Implemented using linkme to aggregate static function registrations from generated code, and an additional evaluation layer that chooses between static and interpreted based on availability