message: Restore default format state of cout after printing with
  std::fixed/setprecision
  backports bitcoin@fd05132e5a5f34046536ef62ba8d130fa3b00c65
diff: @@ -101,6 +101,7 @@ bool benchmark::State::KeepRunning()
  int64_t averageCycles = (nowCycles-beginCycles)/count;
  std::cout << std::fixed << std::setprecision(15) << name << "," << count << "," << minTime << "," << maxTime << "," << average << ","
  << minCycles << "," << maxCycles << "," << averageCycles << "\n";
  + std::cout.copyfmt(std::ios(nullptr));
  return false;
  }
  