anchor.diff:        // If we see a class, add everything its live instance members refer
         // to.  Static members are not relevant, unless we are processing
         // extra dependencies due to mirrors.
  -      void addLiveInstanceMember(_, _element) {
  +      void addLiveInstanceMember(_element) {
           MemberEntity element = _element;
           if (!compiler.resolutionWorldBuilder.isMemberUsed(element)) return;
           if (!isMirrorUsage && !element.isInstanceMember) return;
  
positive.code: 
        ClassEntity cls = element is ClassElement ? element.declaration : element;
        ClassEntity impl = cls is ClassElement ? cls.implementation : cls;
        elementEnvironment.forEachClassMember(cls, addLiveInstanceMember);
        elementEnvironment.forEachSupertype(impl, (InterfaceType type) {
          _collectTypeDependencies(type, elements);
        });
  
negative.code:       } else if (element is LocalFunctionElement) {
          library = element.library;
        } else {
          assert(false, "Unexpected entity: ${element.runtimeType}");
        }
  
        for (Entity dependency in dependentElements) {
  