message: Don't use std::same_v
  It is not supported in C++14.
diff: @@ -60,7 +60,7 @@ class GpuUnaryOpTest : public OpsTestBase {
  NodeDefBuilder builder("some_name", op_name);
  builder.Input(FakeInput(DataTypeToEnum<T>::v()))
  .Attr("T", DataTypeToEnum<T>::v());
  - if (!std::is_same_v<OutT, T>) {
  + if (!std::is_same<OutT, T>::value) {
  builder.Attr("Tout", DataTypeToEnum<OutT>::v());
  }
  TF_ASSERT_OK(builder.Finalize(node_def()));
  