error: these discriminant values do not fit in any supported enum repr type
 --> tests/ui/enum_unsatisfiable.rs:3:5
  |
3 | /     enum Bad {
4 | |         A = -0xFFFF_FFFF_FFFF_FFFF,
5 | |         B = 0xFFFF_FFFF_FFFF_FFFF,
6 | |     }
  | |_____^