patch 8.2.3300: Lua: can only execute on Vim command at a time

Problem:    Lua: can only execute on Vim command at a time.  Not easy to get
            the Vim version.
Solution:   Make vim.command() accept multiple lines.  Add vim.version().
            (Yegappan Lakshmanan, closes #8716)
diff --git a/src/proto/evalfunc.pro b/src/proto/evalfunc.pro
index 5bb38b0..eb89e64 100644
--- a/src/proto/evalfunc.pro
+++ b/src/proto/evalfunc.pro
@@ -17,6 +17,7 @@
 buf_T *get_buf_arg(typval_T *arg);
 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);
 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);