patch 8.1.1120: cannot easily get directory entry matches

Problem:    Cannot easily get directory entry matches.
Solution:   Add the readdir() function. (Yasuhiro Matsumoto, closes #2439)
diff --git a/src/eval.c b/src/eval.c
index 9e93dcf..5f45d69 100644
--- a/src/eval.c
+++ b/src/eval.c
@@ -753,7 +753,7 @@
     return ret;
 }
 
-    static int
+    int
 eval_expr_typval(typval_T *expr, typval_T *argv, int argc, typval_T *rettv)
 {
     char_u	*s;
@@ -966,7 +966,7 @@
  * Save the current typeval in "save_tv".
  * When not used yet add the variable to the v: hashtable.
  */
-    static void
+    void
 prepare_vimvar(int idx, typval_T *save_tv)
 {
     *save_tv = vimvars[idx].vv_tv;
@@ -978,7 +978,7 @@
  * Restore v: variable "idx" to typeval "save_tv".
  * When no longer defined, remove the variable from the v: hashtable.
  */
-    static void
+    void
 restore_vimvar(int idx, typval_T *save_tv)
 {
     hashitem_T	*hi;