Leonardo DiCaprio doesn’t always survive. Titanic? Dead. Django Unchained? Unalive. The Departed? Departed. Romeo and Juliet? We won’t spoil that one for you, but you get the point. His new movie, The Revenant, takes the struggle not to die and really, really goes with it. In the film DiCaprio plays Hugh Glass, a real-life 1820s fur trapper who got mauled by a bear, was robbed and abandoned by his companions, and then spent months crawling to safety through the untamed American wilderness. As for what it took to play the part of Glass, well, let’s just say it involved a lot of snow, bearskins, and numb digits. The production of the film, directed by a fresh-off-Birdman Alejandro Iñárritu, was so complicated and geographically challenging that at times the moviemakers themselves…