patch 8.2.2718: Vim9: no explicit test for using a global function without g:

Problem:    Vim9: no explicit test for using a global function without the g:
            prefix.
Solution:   Add a test case.
diff --git a/src/version.c b/src/version.c
index f22d0cb..961ddea 100644
--- a/src/version.c
+++ b/src/version.c
@@ -751,6 +751,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    2718,
+/**/
     2717,
 /**/
     2716,