The road rage shooting of a three-year-old boy this weekend has two teens facing some serious adult charges — and the little boy fighting for his life.William Hampton and Jerry Hampton each face eight felonies, including first-degree assault after an incident in north St. Louis Saturday evening. Police say Jerry, 17, of the LaSalle Park neighborhood, was the trigger man, while William, 18, of Jennings, was behind the wheel of a 2015 Toyota Avalon, according to the allegations.…