message: Add missing handling of unions in readExtensionRequireType.
diff: @@ -4647,6 +4647,7 @@ void VulkanHppGenerator::readExtensionRequireType(tinyxml2::XMLElement const* el
  }
  break;
  case TypeCategory::Struct:
  + case TypeCategory::Union: // unions are listed together with the structures!
  {
  auto structIt = m_structures.find(name);
  check(structIt != m_structures.end(), line, "failed to find required struct <" + name + ">");
  