Cynthia Weil, 'You've Lost That Lovin' Feelin' Legendary Songwriter Dead at 82

Cynthia Weil, one of the most prolific and successful songwriters of all time, has died ... TMZ has learned. Cynthia's daughter, Dr. Jenn Mann, tells TMZ ... "My mother, Cynthia Weil, was the greatest mother, grandmother and wife our family could…