Summer movies are about heroes. And in this hyper-sharpened environment of the performance arts, apparently it takes one to know one. This is the season of Hollywood hero movies, which… I mostly skip. What’s Tom Cruise in the Mummy got to say to me? Worse, last week he said he was going to do a Top Gun sequel. He’s 54 now. He was 23 the first time out. What will they call this one, Shogun… or No Gun? Then there’s Transformers: The Last Knight, which I recall vigorously defending first as a toy