Macro impl_aref_for_gem_obj 

macro_rules! impl_aref_for_gem_obj {
    (
        impl $( <$( $tparam_id:ident ),+> )? for $type:ty
        $(
            where
                $( $bind_param:path : $bind_trait:path ),+
        )?
    ) => { ... };
}

A macro for implementing AlwaysRefCounted for any GEM object type.

Since all GEM objects use the same refcounting scheme.