add endpoints and clusters for any clusters that were not created fro…

…m walking the listener -> path

agent/xdsv2/resources.go

@@ -60,16 +60,9 @@ func (g *ResourceGenerator) AllResourcesFromIR(proxyState *proxytracker.ProxySta
 	}
 
 	// Now account for Clusters that did not have a destination.
-	for name, cluster := range proxyState.Clusters {
+	for name := range proxyState.Clusters {
 		if _, ok := pr.envoyResources[xdscommon.ClusterType][name]; !ok {
-			envoyClusters, err := pr.makeClusters(name)
-			if err != nil {
-				return nil, fmt.Errorf("failed to generate xDS resources for cluster: %s.  error: %v", cluster, err)
-			}
-
-			for name, envoyCluster := range envoyClusters {
-				pr.envoyResources[xdscommon.ClusterType][name] = envoyCluster
-			}
+			pr.addEnvoyClustersAndEndpointsToEnvoyResources(name)
 		}
 	}