message: Change auto& to int64& for readability.
  Addressing comment in cl/256494838 post submit.
diff: @@ -173,7 +173,7 @@ class Exporter {
  std::string Exporter::UniqueName(llvm::StringRef prefix) {
  // Keep incrementing the counter until we find a unique name.
  std::string name = prefix;
  - auto& prefix_count = name_to_count_[name];
  + int64& prefix_count = name_to_count_[name];
  int64 val = prefix_count;
  while (val != 0) {
  name = (prefix + llvm::Twine(prefix_count)).str();
  