Miley Cyrus stopped smoking weed to speak more coherently — and because she was convinced the habit would eventually end her life. “I kept having this nightmare — I had a dream that I would die during my monologue on ‘SNL’ for some reason, that I would just get so stoned that I just died,” she admitted to Jimmy Fallon on “The Tonight Show” on Wednesday. “I Googled and that’s never happened … no one’s ever died from weed, but no one’s ever smoked as much as I did.” In early May, the 24-year-old boasted, “I haven’t smoked weed in...