patch 7.4.1476
Problem:    Function arguments marked as unused while they are not.
Solution:   Remove UNUSED. (Yegappan Lakshmanan)
diff --git a/src/eval.c b/src/eval.c
index 794ff68..faed315 100644
--- a/src/eval.c
+++ b/src/eval.c
@@ -9217,7 +9217,7 @@
  * "arglistid()" function
  */
     static void
-f_arglistid(typval_T *argvars UNUSED, typval_T *rettv)
+f_arglistid(typval_T *argvars, typval_T *rettv)
 {
     win_T	*wp;
 
@@ -17782,7 +17782,7 @@
  * "screenattr()" function
  */
     static void
-f_screenattr(typval_T *argvars UNUSED, typval_T *rettv)
+f_screenattr(typval_T *argvars, typval_T *rettv)
 {
     int		row;
     int		col;
@@ -17802,7 +17802,7 @@
  * "screenchar()" function
  */
     static void
-f_screenchar(typval_T *argvars UNUSED, typval_T *rettv)
+f_screenchar(typval_T *argvars, typval_T *rettv)
 {
     int		row;
     int		col;
@@ -20969,7 +20969,7 @@
  * "visualmode()" function
  */
     static void
-f_visualmode(typval_T *argvars UNUSED, typval_T *rettv UNUSED)
+f_visualmode(typval_T *argvars, typval_T *rettv)
 {
     char_u	str[2];