message: Implement Arbitrary with BigDigit
diff: @@ -69,13 +69,13 @@ impl Clone for BigUint {
  impl Arbitrary for BigUint {
  fn arbitrary<G: Gen>(g: &mut G) -> Self {
  // Use arbitrary from Vec
  - Self::new(Vec::<u32>::arbitrary(g))
  + biguint_from_vec(Vec::<BigDigit>::arbitrary(g))
  }
  #[allow(bare_trait_objects)] // `dyn` needs Rust 1.27 to parse, even when cfg-disabled
  fn shrink(&self) -> Box<Iterator<Item = Self>> {
  // Use shrinker from Vec
  - Box::new(self.data.shrink().map(|x| BigUint::new(x)))
  + Box::new(self.data.shrink().map(biguint_from_vec))
  }
  }
  