If we have Glen Weldon, co-host of the Pop Culture Happy Hour podcast and author of the marvelous Superman: The Unauthorized Biography on as a guest, you’d better believe we’re gonna go down one of the many fascinating cul-de-sacs in the “super” cinematic universe — in this case 1984’s “Supergirl,” or — as we prefer to think about it — The Adventures of Faye Dunaway’s Fabulous Witch and Her Companions.