AT THE MOVIES, in an early attempt at serious cinema, Tom Hanks (left) stars in the dramedy Punchline. IN MUSIC, metal rules as Bon Jovi’s New Jersey tops a Billboard album chart that includes Guns N’ Roses, Def Leppard, and Metallica. IN BOOKSTORES, The Gunslinger, the first of Stephen King’s Dark Tower series, shoots from No. 1 on the New York Times paperback best-seller list. AND IN THE NEWS, President Reagan signs a bill creating the Department of Veterans Affairs, a move, White House aides admit, to win the support of former soldiers as the election draws near.