/*
 * call-seq:
 *   class.real_superclass => Class
 *
 * Return the immediate superclass of a class or module.  This may be a
 * base class, a singleton class, or a module singleton.
 */
VALUE real_superclass(VALUE self)
{
  VALUE super = RCLASS_SUPER(self);
  rb_include_module(rb_class_of(super), rb_mKernel);
  return super;
}