message: [XLA] Add a bytes read+written table to the end of --xla_hlo_profile.
  This is useful when tuning fusion heuristics -- you expect this number
  to go down (even if the total runtime doesn't go down, due to suboptimal
  emitters).
diff: @@ -169,6 +169,23 @@ string HumanReadableProfileBuilder::ToString() const {
  StrAppend(&s, table.MakeReport(CyclesToMicroseconds(total_cycles_)));
  }
  }
  +
  + if (total_bytes > 0) {
  + MetricTableReport table;
  + table.SetMetricName("MiB read+written");
  + table.SetEntryName("ops");
  + table.SetShowCategoryTable();
  + for (const auto& op : op_infos_) {
  + MetricTableReport::Entry entry;
  + entry.text = op.name;
  + entry.short_text = op.short_name;
  + entry.category_text = op.category;
  + entry.metric = static_cast<double>(op.bytes_accessed) / (1 << 20);
  + table.AddEntry(std::move(entry));
  + }
  + StrAppend(&s,
  + table.MakeReport(static_cast<double>(total_bytes) / (1 << 20)));
  + }
  return s;
  }
  