message: [XLA] Add stringification to BatchNormTestParam.
  This way when a test fails, it prints out useful information about the
  failure, instead of
  "<48-byte object with these bytes: de ad be ef ...>"
diff: @@ -39,6 +39,7 @@ limitations under the License.
  #include "tensorflow/compiler/xla/tests/test_utils.h"
  #include "tensorflow/compiler/xla/util.h"
  #include "tensorflow/compiler/xla/xla_data.pb.h"
  +#include "tensorflow/core/lib/strings/str_util.h"
  #include "tensorflow/core/platform/logging.h"
  #include "tensorflow/core/platform/test.h"
  #include "tensorflow/core/platform/types.h"
  @@ -203,6 +204,15 @@ struct BatchNormTestParam {
  int64 feature_index;
  float random_value_mean;
  float random_value_var;
  +
  + friend ::std::ostream& operator<<(::std::ostream& os,
  + const BatchNormTestParam& p) {
  + os << "bounds={" << tensorflow::str_util::Join(p.bounds, ", ") << "}, ";
  + os << "feature_index=" << p.feature_index << ", ";
  + os << "random_value_mean=" << p.random_value_mean << ", ";
  + os << "random_value_var=" << p.random_value_var;
  + return os;
  + }
  };
  // Tests to test the fused operation of BatchNorm.
  