This imprecise implementation turned out to cause linkage errors, e.g. when type variables in the signatures of member methods were inappropriately erased. For the time being we accept that $default methods despite having erased signatures in keeping with their JVM representation can contain expressions whose types make reference to their
surrounding function or class' type variables, even though they should be out of scope since $default methods are static and don't have type parameters, and need to cope with the inconsistency in QL.
