CombinedIndexBuildItem to receive ClassInfo on inherited interfaces

[oztimpower]

Description
For example, per Amazon Lambda extension documentation updates:

Writing Skills with the Amazon Alexa ASK SDK v2

The starting point for an Alexa Skill on AWS Lambda is typically via subclassing SkillStreamHandler, which implements the RequestStreamHandler::requestHandler method. If you examine the source code for this class it is very simple, and can be implemented directly without this helper base class.

NOTE: Quarkus requires a direct implementation of RequestStreamHandler, as the build process will scan only directly implemented interfaces, inherited interfaces will not be seen.

Implementation ideas

Generated ClassInfo, as part of the CombinedIndexBuildItem, to include all inherited interfaces. It currently only contains directly implemented interfaces.

For example in Amazon Lambda, AmazonLambdaProcesser, the code below looking for a specific interface implementation, would see the inherited interfaces.

Collection<ClassInfo> allKnownImplementors = combinedIndexBuildItem.getIndex().getAllKnownImplementors(REQUEST_HANDLER);

    @BuildStep
    List<AmazonLambdaBuildItem> discover(CombinedIndexBuildItem combinedIndexBuildItem,
            Optional<ProvidedAmazonLambdaHandlerBuildItem> providedLambda,
            BuildProducer<AdditionalBeanBuildItem> additionalBeanBuildItemBuildProducer,
            BuildProducer<ReflectiveHierarchyBuildItem> reflectiveHierarchy,
            BuildProducer<ReflectiveClassBuildItem> reflectiveClassBuildItemBuildProducer) throws BuildException {
  
      Collection<ClassInfo> allKnownImplementors = combinedIndexBuildItem.getIndex().getAllKnownImplementors(REQUEST_HANDLER);

      Collection<ClassInfo> allKnownStreamImplementors = combinedIndexBuildItem.getIndex()
                .getAllKnownImplementors(REQUEST_STREAM_HANDLER);

/cc @gsmet
/cc @patriot1burke

[geoand]

I think this request is essentially this issue: smallrye/jandex#65

[gsmet]

For now, I would just also get the classes implementing SkillStreamHandler and merge them with the others.

Not ideal and we should definitely pursue this on the Jandex side but good enough for this particular case.

[oztimpower]

Closing as a workaround has been implemented in #7985, and as above there is already a FR open on smallrye/jandex#65