One measure of the affection (and, yes, lust) that has accrued to Robert Redford over his decades in movies is, when he walks into a bank in “The Old Man and the Gun,” we reflexively wonder, is he “walking” like an old man or does he, at 82, now walk like an old man? Actually, in keeping with the delicacy of the acting ego, Redford is playing younger than his age.