3. Add primitives

This is a wrapper around add_primitives, created so that s9ext.h doesn't need to be included.

<<scheme_function_declarations>>=

void monolith_scheme_add_primitives(char *name, S9_PRIM *p);

<<scheme_functions>>=

void monolith_scheme_add_primitives(char *name, S9_PRIM *p)
{
    add_primitives(name, p);
}