scope generalizedCIComparator

// non-strings must be Comparable to each other
// probably this is not that useful after all

static simplyCached #C generalizedCIComparator() {
  ret new C;
}

final sclass #C implements Comparator<O> {
  public int compare(O o1, O o2) {
    if (o1 cast S)
      if (o2 cast S)
        ret betterCIComparator().compare(o1, o2);
      else
        ret -1;
    else
      if (o2 instanceof S)
        ret 1;
    else
      ret cmp(o1, o2);
  }
}

Began life as a copy of #1014136