message: Add FIXMEs for uint size bugs
diff: @@ -146,7 +146,7 @@ pub fn is_subtype(sty: &Type, ty: &Type) -> bool {
  (sty, ty) if sty == ty => true,
  // S-SINGLETON-UINT
  - // FIXME: Use intersection types instead
  + // FIXME: This is actually treating the singleton as a positive range from zero!
  (&Type::SingletonUInt(sn), &Type::SingletonUInt(n)) if sn <= n => true,
  // S-UINT
  @@ -415,6 +415,7 @@ pub fn type_of(env: &Env, expr: &Expr) -> Result<Type, TypeError> {
  }
  }
  // T-ARITH-...
  + // FIXME: These rules are incompatible with the way we formulated S-SINGLETON-UINT
  Binop::Add | Binop::Sub | Binop::Mul | Binop::Div => {
  // T-ARITH-LHS
  if is_subtype(&lhs_ty, &rhs_ty) && is_numeric(&rhs_ty) {
  