 need to
    populate all the various VTable entries.

    <h2>Passing a reference to a virtual base class</h2>

    <p>
      When we pass a reference to a virtual base class, we have to
      slice it off at the right offset, since the method expecting the
      base class doesn't know it might be virtual.
    </p>

    <h2>Polymorphic Function Pointers</h2>

    Polymorphic function pointers require enough information to know
    where to find themselves int he VTable. However, because the
    compiler k