The problem is with that part, as for “look at C header” part you still need full C compiler and translating between C calls and NIFs isn’t that trivial matter in many cases.
If anything there could be bindings for libffi (there is even old EEP 0007 that never landed). This would allow loading native dynamic libraries at runtime and extract symbols from that, that would help with a lot of trivial cases (like for example getting euid in Erlang code), but that will work only in super trivial cases.
