message: bls12_381: Remove unnecessary clones
  The structs in question all implement Copy.
diff: @@ -46,12 +46,12 @@ impl MillerLoopResult {
  // https://eprint.iacr.org/2009/565.pdf
  #[must_use]
  fn cyclotomic_square(f: Fp12) -> Fp12 {
  - let mut z0 = f.c0.c0.clone();
  - let mut z4 = f.c0.c1.clone();
  - let mut z3 = f.c0.c2.clone();
  - let mut z2 = f.c1.c0.clone();
  - let mut z1 = f.c1.c1.clone();
  - let mut z5 = f.c1.c2.clone();
  + let mut z0 = f.c0.c0;
  + let mut z4 = f.c0.c1;
  + let mut z3 = f.c0.c2;
  + let mut z2 = f.c1.c0;
  + let mut z1 = f.c1.c1;
  + let mut z5 = f.c1.c2;
  let (t0, t1) = fp4_square(z0, z1);
  @@ -113,7 +113,7 @@ impl MillerLoopResult {
  tmp.conjugate()
  }
  - let mut f = self.0.clone();
  + let mut f = self.0;
  let mut t0 = f
  .frobenius_map()
  .frobenius_map()
  @@ -124,7 +124,7 @@ impl MillerLoopResult {
  Gt(f.invert()
  .map(|mut t1| {
  let mut t2 = t0 * t1;
  - t1 = t2.clone();
  + t1 = t2;
  t2 = t2.frobenius_map().frobenius_map();
  t2 *= t1;
  t1 = cyclotomic_square(t2).conjugate();
  