patch 8.2.4285: Vim9: type of item in for loop not checked properly

Problem:    Vim9: type of item in for loop not checked properly.
Solution:   Adjust the type checking. (closes #9683)
diff --git a/src/vim9compile.c b/src/vim9compile.c
index 9ad1e7d..9dbd119 100644
--- a/src/vim9compile.c
+++ b/src/vim9compile.c
@@ -386,7 +386,7 @@
  * If "actual_is_const" is TRUE then the type won't change at runtime, do not
  * generate a TYPECHECK.
  */
-    static int
+    int
 need_type_where(
 	type_T	*actual,
 	type_T	*expected,