patch 8.0.0737: crash when X11 selection is very big

Problem:    Crash when X11 selection is very big.
Solution:   Use static items instead of allocating them.  Add callbacks.
            (Ozaki Kiichi)

src/version.c

@@ -769,6 +769,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    737,
 /**/
     736,
 /**/