LUCENE-5486: allow out-of-order collector selection with query time joins

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/trunk@1573615 13f79535-47bb-0310-9956-ffa450edef68

lucene/join/src/java/org/apache/lucene/search/join/TermsIncludingScoreQuery.java

@@ -140,6 +140,13 @@ class TermsIncludingScoreQuery extends Query {
         return new ComplexExplanation(false, 0.0f, "Not a match");
       }
 
+      @Override
+      public boolean scoresDocsOutOfOrder() {
+        // We have optimized impls below if we are allowed
+        // to score out-of-order:
+        return true;
+      }
+
       @Override
       public Query getQuery() {
         return TermsIncludingScoreQuery.this;