Method get_vtable_pointers

Internal function that returns metadata of all functions in the vtable at address `mem_location` ## Return value Returns a vector of tuples. If `res` is a return tuple of this function, the fields denote: `res.0`: address of the lea instruction `res.1`: address of the called function `res.2`: type of invocation (either `InvocationType::ProcedureReference` or `InvocationType::VTable`

(
        &self,
        graph: &StableGraph<Rc<RefCell<Procedure<P>>>, Rc<RefCell<Invocation<I, F>>>>,
        proc_index: &HashMap<u64, NodeIndex<u32>>,
        prc: &Procedure<P>,
        lea_addre