if (pre == Type.localThisType || pre.symbol().isRoot())
if (pre.isSameAs(Type.localThisType) || pre.symbol().isRoot())
    public Tree mkRef(int pos, Type pre, Symbol sym) {	if (pre == Type.localThisType || pre.symbol().isRoot())	    return Ident(pos, sym);	else	    return Select(pos, mkStableId(pos, pre), sym);    }