Snatched begins with Amy Schumer, her second leading role after 2015’s Trainwreck, in a familiar comic persona from her standup, film and TV work: the Messy White Girl, whose oblivious, entitled sense of privilege is expressed with a malice-free, faint irony. Emily (Schumer) is fired from her retail job (after a funny bait-and-switch with screenwriter Katie Dippold) and dumped by her rockstar boyfriend, responding to the slights with hurt, haughty denial. Left with no-one to join her on a non-refundable resort trip to Ecuador, and conveniently moved by memories of her divorced homebody mother (Goldie Hawn) in happier, more fun-loving…