At a recent screening of “Game Night,” a goofily larky comedy starring Jason Bateman and Rachel McAdams, the audience cringed in distaste when McAdams’s character playfully stuck a handgun in her mouth, unaware that it was real and loaded. Meanwhile, in a theater across the multiplex, an audience eager to see the visionary world-building of “Black Panther” first had to slog through trailers for a new “Mission: Impossible” movie, a “Deadpool” sequel and next week’s remake of “Death Wish,” in which Tom Cruise, Josh Brolin and Bruce Willis can be seen brandishing firearms with varying degrees of macho swagger and ironic snark.