Drew Barrymore, who overcame a tumultuous youth to become an A-list actress and high-powered producer, is profiled. The celeb rose to fame at age 6 on the strength of “E.T.,” only to land in rehab by 13. Included: insights from friend Amy Heckerling, “Charlie's Angels” director McG, film critic Roger Ebert and biographer Leah Furman.