message: Simplify Rem<iN> for BigInt
  The input sign is already checked in `uabs`, and we don't care beyond
  that, so these don't need the `if`-`else` repetition.
diff: @@ -2045,24 +2045,16 @@ impl Rem<i32> for BigInt {
  #[inline]
  fn rem(self, other: i32) -> BigInt {
  - if other >= 0 {
  - self % other as u32
  - } else {
  self % other.uabs()
  }
  }
  -}
  impl RemAssign<i32> for BigInt {
  #[inline]
  fn rem_assign(&mut self, other: i32) {
  - if other >= 0 {
  - *self %= other as u32;
  - } else {
  *self %= other.uabs();
  }
  }
  -}
  impl Rem<BigInt> for i32 {
  type Output = BigInt;
  @@ -2082,24 +2074,16 @@ impl Rem<i64> for BigInt {
  #[inline]
  fn rem(self, other: i64) -> BigInt {
  - if other >= 0 {
  - self % other as u64
  - } else {
  self % other.uabs()
  }
  }
  -}
  impl RemAssign<i64> for BigInt {
  #[inline]
  fn rem_assign(&mut self, other: i64) {
  - if other >= 0 {
  - *self %= other as u64;
  - } else {
  *self %= other.uabs();
  }
  }
  -}
  impl Rem<BigInt> for i64 {
  type Output = BigInt;
  @@ -2119,24 +2103,16 @@ impl Rem<i128> for BigInt {
  #[inline]
  fn rem(self, other: i128) -> BigInt {
  - if other >= 0 {
  - self % other as u128
  - } else {
  self % other.uabs()
  }
  }
  -}
  impl RemAssign<i128> for BigInt {
  #[inline]
  fn rem_assign(&mut self, other: i128) {
  - if other >= 0 {
  - *self %= other as u128;
  - } else {
  *self %= other.uabs();
  }
  }
  -}
  impl Rem<BigInt> for i128 {
  type Output = BigInt;
  