8306785: fix deficient spliterators for Sequenced Collections

Reviewed-by: psandoz

src/java.base/share/classes/java/util/ReverseOrderDequeView.java

@@ -61,7 +61,7 @@ class ReverseOrderDequeView<E> implements Deque<E> {
     }
 
     public Spliterator<E> spliterator() {
-        return Spliterators.spliteratorUnknownSize(base.descendingIterator(), 0);
+        return Spliterators.spliterator(this, Spliterator.ORDERED);
     }
 
     // ========== Collection ==========