patch 8.2.1154: Vim9: crash when using imported function

Problem:    Vim9: crash when using imported function.
Solution:   Check for a function type.  Set the script context when calling a
            function. (closes #6412)
diff --git a/src/proto/scriptfile.pro b/src/proto/scriptfile.pro
index b5b8aae..fd4c104 100644
--- a/src/proto/scriptfile.pro
+++ b/src/proto/scriptfile.pro
@@ -1,9 +1,9 @@
 /* scriptfile.c */
 void estack_init(void);
 estack_T *estack_push(etype_T type, char_u *name, long lnum);
-void estack_push_ufunc(ufunc_T *ufunc, long lnum);
+estack_T *estack_push_ufunc(ufunc_T *ufunc, long lnum);
 int estack_top_is_ufunc(ufunc_T *ufunc, long lnum);
-void estack_pop(void);
+estack_T *estack_pop(void);
 char_u *estack_sfile(void);
 void ex_runtime(exarg_T *eap);
 int do_in_path(char_u *path, char_u *name, int flags, void (*callback)(char_u *fname, void *ck), void *cookie);