code: private void addRelatedInstance(FunctionType constructor, JSTypeBitSet related) {
      checkArgument(constructor.hasInstanceType(),
          "Constructor %s without instance type.", constructor);
      ObjectType instanceType = constructor.getInstanceType();
      addRelatedType(instanceType, related);
    }
docs: Adds the instance of the given constructor, its implicit prototype and all
  its related types to the given bit set.