patch 8.2.4912: using execute() to define a lambda doesn't work

Problem:    Using execute() to define a lambda doesn't work. (Ernie Rael)
Solution:   Put the getline function in evalarg. (closes #10375)
diff --git a/src/proto/evalfunc.pro b/src/proto/evalfunc.pro
index 4e9ad5b..5103588 100644
--- a/src/proto/evalfunc.pro
+++ b/src/proto/evalfunc.pro
@@ -17,11 +17,12 @@
 win_T *get_optional_window(typval_T *argvars, int idx);
 void execute_redir_str(char_u *value, int value_len);
 void execute_cmds_from_string(char_u *str);
+char_u *get_list_line(int c, void *cookie, int indent, getline_opt_T options);
 void execute_common(typval_T *argvars, typval_T *rettv, int arg_off);
 void f_exists(typval_T *argvars, typval_T *rettv);
 void f_has(typval_T *argvars, typval_T *rettv);
-void f_len(typval_T *argvars, typval_T *rettv);
 int dynamic_feature(char_u *feature);
+void f_len(typval_T *argvars, typval_T *rettv);
 void mzscheme_call_vim(char_u *name, typval_T *args, typval_T *rettv);
 void range_list_materialize(list_T *list);
 long do_searchpair(char_u *spat, char_u *mpat, char_u *epat, int dir, typval_T *skip, int flags, pos_T *match_pos, linenr_T lnum_stop, long time_limit);