Given recent events, dystopian films such as “1984” and “Planet of the Apes” are seeming more and more like documentaries than flights of fancy vision. But one thing hasn’t changed: They’re a lot of fun, even if now they might induce an extra heaping of increased panic. From the days of “Metropolis” through next month’s “Blade Runner 2049,” filmmakers have warned against totalitarian and fascist states, nuclear war, climate change disasters and loss of freedom, often with a bleak, eye-popping vision.