patch 8.0.0537: illegal memory access with :z and large count

Problem:    Illegal memory access with :z and large count.
Solution:   Check for number overflow, using long instead of int. (Dominique
            Pelle, closes #1612)

src/version.c

@@ -764,6 +764,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    537,
 /**/
     536,
 /**/