patch 8.1.0519: cannot save and restore the tag stack

Problem:    Cannot save and restore the tag stack.
Solution:   Add gettagstack() and settagstack(). (Yegappan Lakshmanan,
            closes #3604)
diff --git a/src/proto/dict.pro b/src/proto/dict.pro
index ede4f87..21c8d6d 100644
--- a/src/proto/dict.pro
+++ b/src/proto/dict.pro
@@ -1,5 +1,6 @@
 /* dict.c */
 dict_T *dict_alloc(void);
+dict_T *dict_alloc_id(alloc_id_T id);
 dict_T *dict_alloc_lock(int lock);
 int rettv_dict_alloc(typval_T *rettv);
 void rettv_dict_set(typval_T *rettv, dict_T *d);