Mike Birbiglia has found that he can make a living off a personal crisis.Since 2008, Birbiglia, a longtime comedian and more recently an indie film director and star, has performed stand-up comedy shows on and off-Broadway about his struggles with sleepwalking, his recovery from bladder cancer and his path toward fatherhood. But his latest, “The Old Man & the Pool,” a monologue about confronting his own mortality, might be among his most candid. (The show opens on Broadway Nov. 13 at the Vivian Beaumont Theater at Lincoln Center.)