TOM CRUISE has been doing his own stunts for years . . . but he may have performed his most dangerous stunt yet for"Mission: Impossible - Rogue Nation".There's a scene where Tom clings to the outside of an airplane as it takes flight . . . and yes, he REALLY DID IT. He was strapped to the plane, of course. But it's still pretty insane. And they had to do EIGHT TAKES.