patch 8.2.5106: default cmdwin mappings are re-mappable

Problem:    Default cmdwin mappings are re-mappable.
Solution:   Make the default mappings not re-mappable. (closes #10580)  Use
            symbols for the first do_map() argument.
diff --git a/src/proto/map.pro b/src/proto/map.pro
index f92339f..5caa859 100644
--- a/src/proto/map.pro
+++ b/src/proto/map.pro
@@ -22,7 +22,7 @@
 void f_mapcheck(typval_T *argvars, typval_T *rettv);
 void f_mapset(typval_T *argvars, typval_T *rettv);
 void init_mappings(void);
-void add_map(char_u *map, int mode);
+void add_map(char_u *map, int mode, int nore);
 int langmap_adjust_mb(int c);
 void langmap_init(void);
 void langmap_set(void);