At the end of the apocalypse, after the sun has fried every flower and tree, as the last skyscraper turns to dust, when each extant cockroach has gone belly-up with x’es for eyes, there will be one man standing tall, or somewhat tall: Tom Cruise is forever, and if that idea may have seemed mortifying 40-odd years ago, when he was mugging his way through thinly disguised navy recruitment ads or grinning and grinding in his skivvies to Bob Seger’s “Old Time Rock & Roll,” it’s more palatable now.