patch 8.0.0584: memory leak when executing quickfix tests

Problem:    Memory leak when executing quickfix tests.
Solution:   Free the list reference. (Yegappan Lakshmanan)

Author: brammool

src/quickfix.c

@@ -4934,6 +4934,9 @@ qf_free_stack(win_T *wp, qf_info_T *qi)
 	 * location list */
 	qf_info_T *new_ll = ll_new_list();
 
+	/* first free the list reference in the location list window */
+	ll_free_all(&orig_wp->w_llist_ref);
+
 	orig_wp->w_llist_ref = new_ll;
 	if (llwin != NULL)
 	{

src/version.c

@@ -764,6 +764,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    584,
 /**/
     583,
 /**/