patch 9.0.0470: in :def function all closures in loop get the same variables

Problem:    In a :def function all closures in a loop get the same variables.
Solution:   When in a loop and a closure refers to a variable declared in the
            loop, prepare for making a copy of variables for each closure.
diff --git a/src/version.c b/src/version.c
index 8b4efd7..3f832ad 100644
--- a/src/version.c
+++ b/src/version.c
@@ -704,6 +704,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    470,
+/**/
     469,
 /**/
     468,