patch 8.0.0256: missing changes to one file breaks test

Problem:    Tests fail because some changes were not included.
Solution:   Add changes to evalfunc.c

src/version.c

@@ -764,6 +764,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    256,
 /**/
     255,
 /**/