libstrat: enable -Wextra, -Werror

This caught an embarrassingly large number of bugs.

libraries/libstratosphere/source/sf/cmif/sf_cmif_domain_service_object.cpp

@@ -160,6 +160,8 @@ namespace ams::sf::cmif {
     }
 
     void DomainServiceObjectProcessor::SetOutObjects(const cmif::ServiceDispatchContext &ctx, const HipcRequest &response, ServiceObjectHolder *out_objects, DomainObjectId *selected_ids) {
+        AMS_UNUSED(ctx, response);
+
         const size_t num_out_objects = this->GetOutObjectCount();
 
         /* Copy input object IDs from command impl (normally these are Invalid, in mitm they should be set). */