LOS ANGELES-Fans were given a sneak peek Monday at the hotly-anticipated sequel to “Trainspotting,” 20 years after it delighted critics and shocked Hollywood with its vivid depiction of Scotland’s heroin subculture. The iconic black comedy’s original cast - fronted by Ewan McGregor, Ewen Bremner, Jonny Lee Miller and Robert Carlyle - have been reunited for the new film, which has the working title “T2.” The sequel also sees the return of director Danny Boyle, who has become a household name over the last two decades with a host of critical and commercial hits including “28 Days Later” and “Slumdog Millionaire.”