patch 8.0.0393: order of duplicate tags is not preserved

Problem:    When the same tag appears more than once, the order is
            unpredictable. (Charles Campbell)
Solution:   Besides using a dict for finding duplicates, use a grow array for
            keeping the tags in sequence.

src/version.c

@@ -764,6 +764,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    393,
 /**/
     392,
 /**/