message: [golang] Create missing namespace directory structure
diff: @@ -1357,8 +1357,10 @@ class GoGenerator : public BaseGenerator {
  while (code.length() > 2 && code.substr(code.length() - 2) == "\n\n") {
  code.pop_back();
  }
  - std::string filename =
  - namer_.Directories(ns) + namer_.File(def, SkipFile::Suffix);
  + std::string directory = namer_.Directories(ns);
  + std::string file = namer_.File(def, SkipFile::Suffix);
  + EnsureDirExists(directory);
  + std::string filename = directory + file;
  return SaveFile(filename.c_str(), code, false);
  }
  