patch 9.0.2182: Vim9: need a way to reserve future extension

Problem:  Vim9: need a way to reserve future extension
Solution: reserve double underscore prefix for future use
          (Yegappan Lakshmanan)

related: #13238
closes: #13742

Signed-off-by: Yegappan Lakshmanan <yegappan@yahoo.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/src/version.c b/src/version.c
index 316e638..6120c53 100644
--- a/src/version.c
+++ b/src/version.c
@@ -705,6 +705,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    2182,
+/**/
     2181,
 /**/
     2180,