patch 8.2.3235: cannot use lambda in {} block in user command

Problem:    Cannot use lambda in {} block in user command. (Martin Tournoij)
Solution:   Do not go over the end of the lambda.
diff --git a/src/testdir/test_usercommands.vim b/src/testdir/test_usercommands.vim
index df88937..173b23e 100644
--- a/src/testdir/test_usercommands.vim
+++ b/src/testdir/test_usercommands.vim
@@ -632,6 +632,13 @@
   call assert_equal('more', g:didmore)
   unlet g:didit
   unlet g:didmore
+  delcommand DoSomething
+
+  command DoMap {
+	echo [1, 2, 3]->map((_, v) => v + 1)
+    }
+  DoMap
+  delcommand DoMap
 
   let lines =<< trim END
       command DoesNotEnd {