message: Use biguint_from_vec in bigint_from_slice
diff: @@ -8,7 +8,6 @@ use traits::{One, Zero};
  use biguint::biguint_from_vec;
  use biguint::BigUint;
  -use biguint::IntDigits;
  use bigint::BigInt;
  use bigint::Sign;
  @@ -259,10 +258,7 @@ pub fn mac_digit(acc: &mut [BigDigit], b: &[BigDigit], c: BigDigit) {
  }
  fn bigint_from_slice(slice: &[BigDigit]) -> BigInt {
  - let mut u = BigUint::zero();
  - u.digits_mut().extend_from_slice(slice);
  - u.normalize();
  - BigInt::from(u)
  + BigInt::from(biguint_from_vec(slice.to_vec()))
  }
  /// Three argument multiply accumulate:
  