message: Fix TypeAttrId constructors
diff: @@ -57,13 +57,13 @@ const char kCastToFp32[] = "CastToFp32";
  struct TypeAttrId {
  static const int kSingleType = -1;
  - explicit TypeAttrId(const string& _attr_name = "",
  - int _type_index = kSingleType)
  + explicit TypeAttrId(const string& _attr_name, int _type_index = kSingleType)
  : attr_name(_attr_name),
  type_index(_type_index),
  fixed_type(DT_INVALID) {}
  - explicit TypeAttrId(DataType _fixed_type) : fixed_type(_fixed_type) {}
  + explicit TypeAttrId(DataType _fixed_type)
  + : attr_name(), type_index(kSingleType), fixed_type(_fixed_type) {}
  bool operator==(const TypeAttrId& other) const {
  return attr_name == other.attr_name && type_index == other.type_index &&
  