patch 8.2.1744: Vim9: using ":const!" is weird
Problem: Vim9: using ":const!" is weird.
Solution: Use "var" - "final" - "const" like Dart. "let" still works for
now.
diff --git a/src/proto/evalvars.pro b/src/proto/evalvars.pro
index 569a73a..6965508 100644
--- a/src/proto/evalvars.pro
+++ b/src/proto/evalvars.pro
@@ -14,6 +14,7 @@
void prepare_vimvar(int idx, typval_T *save_tv);
void restore_vimvar(int idx, typval_T *save_tv);
list_T *heredoc_get(exarg_T *eap, char_u *cmd, int script_get);
+void ex_var(exarg_T *eap);
void ex_let(exarg_T *eap);
int ex_let_vars(char_u *arg_start, typval_T *tv, int copy, int semicolon, int var_count, int flags, char_u *op);
char_u *skip_var_list(char_u *arg, int include_type, int *var_count, int *semicolon, int silent);