message: [XLA] Redesign: implement Conj.
diff: @@ -1083,7 +1083,9 @@ XlaOp XlaBuilder::Complex(
  return BinaryOp(HloOpcode::kComplex, real, imag, broadcast_dimensions);
  }
  -XlaOp XlaBuilder::Conj(const XlaOp& operand) { return UnimplementedOp(); }
  +XlaOp XlaBuilder::Conj(const XlaOp& operand) {
  + return Complex(Real(operand), Neg(Imag(operand)));
  +}
  XlaOp XlaBuilder::Sub(const XlaOp& lhs, const XlaOp& rhs,
  tensorflow::gtl::ArraySlice<int64> broadcast_dimensions) {
  