message: Filter (implicitly) required "FlagBits"-enums that are explicitly listed later on in an extension.
diff: @@ -2695,7 +2695,9 @@ void VulkanHppGenerator::appendEnums( std::string & str ) const
  for ( auto const & type : extIt.second->second.types )
  {
  auto enumIt = m_enums.find( type );
  - if ( enumIt != m_enums.end() )
  + // some "FlagBits"-enums are implicitly added to a feature, as the corresponding "Flags"-enum needs it !!
  + // => it can happen that a "FlagBits"-enum explicitly listed for an extension is already listed with a feature!
  + if ( enumIt != m_enums.end() && listedEnums.insert( type ).second )
  {
  enumIts.push_back( enumIt );
  }
  @@ -2712,9 +2714,6 @@ void VulkanHppGenerator::appendEnums( std::string & str ) const
  str += enter + "\n //=== " + extIt.second->first + " ===\n";
  for ( auto enumIt : enumIts )
  {
  - assert( listedEnums.find( enumIt->first ) == listedEnums.end() );
  - listedEnums.insert( enumIt->first );
  -
  str += "\n";
  appendEnum( str, *enumIt );
  appendEnumToString( str, *enumIt );
  