Must Articles 43 EC and 48 EC (now Articles 49 TFEU and 54 TFEU) be interpreted as precluding national legislation on the basis of which a parent company established in a Member State is not allowed to deduct interest in respect of a loan associated with a capital contribution made to a subsidiary established in another Member State, whereas that deduction could have been availed of if that subsidiary had been included with that parent company in a single tax entity — with characteristics such as those of a Netherlands single tax entity — in view of the fact that, in that case, by reason of consolidation, there would be no obvious association with such a capital contribution?