message: Find first_indices in a more modern manner
  This is a no-op change, but it hopefully makes this complex code a little easier to understand.
diff: @@ -15,6 +15,7 @@ limitations under the License.
  #include "tensorflow/core/common_runtime/direct_session.h"
  +#include <algorithm>
  #include <atomic>
  #include <string>
  #include <vector>
  @@ -856,14 +857,11 @@ Status DirectSession::Run(const RunOptions& run_options,
  // output_names[i] == output_names[j].
  std::vector<int> first_indices;
  if (!unique_outputs) {
  - first_indices.resize(output_names.size());
  - for (int i = 0; i < output_names.size(); ++i) {
  - for (int j = 0; j <= i; ++j) {
  - if (output_names[i] == output_names[j]) {
  - first_indices[i] = j;
  - break;
  - }
  - }
  + first_indices.reserve(output_names.size());
  + for (const auto& name : output_names) {
  + first_indices.push_back(
  + std::find(output_names.begin(), output_names.end(), name) -
  + output_names.begin());
  }
  }
  outputs->clear();
  