message: Work around older compilers with sparse initializer issues.
diff: @@ -152,7 +152,9 @@ TEST(ReferenceComponentTest, MatchesMetatypeTest) {
  }
  }
  { // kCallable matches only kFunction and kTask
  - const ReferenceComponent component{.metatype = SymbolMetaType::kCallable};
  + const ReferenceComponent component{.identifier = "",
  + .ref_type = ReferenceType::kUnqualified,
  + .metatype = SymbolMetaType::kCallable};
  for (const auto& other :
  {SymbolMetaType::kFunction, SymbolMetaType::kTask}) {
  const auto status = component.MatchesMetatype(other);
  