Function R_registerRoutines_C 

unsafe extern "C" fn R_registerRoutines_C(
    info: *mut DllInfo,
    croutines: *const c_void,
    callRoutines: *const R_CallMethodDef_C,
    fortranRoutines: *const c_void,
    externalRoutines: *const c_void,
) -> c_int

Register native routines using legacy ABI types.