Update runtime files.
diff --git a/runtime/doc/vim9.txt b/runtime/doc/vim9.txt
index 576456a..1782f17 100644
--- a/runtime/doc/vim9.txt
+++ b/runtime/doc/vim9.txt
@@ -1,4 +1,4 @@
-*vim9.txt* For Vim version 8.2. Last change: 2021 Sep 13
+*vim9.txt* For Vim version 8.2. Last change: 2021 Nov 22
VIM REFERENCE MANUAL by Bram Moolenaar
@@ -821,6 +821,10 @@
For loop ~
+The loop variable must not exist yet: >
+ var i = 1
+ for i in [1, 2, 3] # Error!
+
Legacy Vim script has some tricks to make a for loop over a list handle
deleting items at the current or previous item. In Vim9 script it just uses
the index, if items are deleted then items in the list will be skipped.