u3: enable ASan for u3r_mean and friends
u3: enable ASan for u3r_mean and friends

jfranklin9000/urbit,jfranklin9000/urbit,urbit/urbit,urbit/urbit,ngzax/urbit,urbit/urbit,urbit/urbit,ngzax/urbit,jfranklin9000/urbit,urbit/urbit,ngzax/urbit,ngzax/urbit,ngzax/urbit,jfranklin9000/urbit,jfranklin9000/urbit,ngzax/urbit,jfranklin9000/urbit,ngzax/urbit,urbit/urbit,jfranklin9000/urbit,urbit/urbit