patch 9.0.0683: cannot specify a time for :echowindow

Problem:    Cannot specify a time for :echowindow.
Solution:   A count can be used to specify the display time. Add
            popup_findecho().
diff --git a/src/proto/popupwin.pro b/src/proto/popupwin.pro
index 12be54f..1ff9950 100644
--- a/src/proto/popupwin.pro
+++ b/src/proto/popupwin.pro
@@ -57,6 +57,7 @@
 int popup_is_popup(win_T *wp);
 win_T *popup_find_preview_window(void);
 win_T *popup_find_info_window(void);
+void f_popup_findecho(typval_T *argvars, typval_T *rettv);
 void f_popup_findinfo(typval_T *argvars, typval_T *rettv);
 void f_popup_findpreview(typval_T *argvars, typval_T *rettv);
 int popup_create_preview_window(int info);
@@ -67,7 +68,7 @@
 void popup_show_message_win(void);
 int popup_message_win_visible(void);
 void popup_hide_message_win(void);
-void start_echowindow(void);
+void start_echowindow(int time_sec);
 void end_echowindow(void);
 int popup_win_closed(win_T *win);
 void popup_set_title(win_T *wp);
diff --git a/src/proto/vim9cmds.pro b/src/proto/vim9cmds.pro
index 4d9e983..bd2b5c2 100644
--- a/src/proto/vim9cmds.pro
+++ b/src/proto/vim9cmds.pro
@@ -25,7 +25,7 @@
 char_u *compile_eval(char_u *arg, cctx_T *cctx);
 int get_defer_var_idx(cctx_T *cctx);
 char_u *compile_defer(char_u *arg_start, cctx_T *cctx);
-char_u *compile_mult_expr(char_u *arg, int cmdidx, cctx_T *cctx);
+char_u *compile_mult_expr(char_u *arg, int cmdidx, long cmd_count, cctx_T *cctx);
 char_u *compile_put(char_u *arg, exarg_T *eap, cctx_T *cctx);
 char_u *compile_exec(char_u *line_arg, exarg_T *eap, cctx_T *cctx);
 char_u *compile_script(char_u *line, cctx_T *cctx);
diff --git a/src/proto/vim9instr.pro b/src/proto/vim9instr.pro
index f0298f9..87914f3 100644
--- a/src/proto/vim9instr.pro
+++ b/src/proto/vim9instr.pro
@@ -60,6 +60,7 @@
 int generate_STRINGMEMBER(cctx_T *cctx, char_u *name, size_t len);
 int generate_ECHO(cctx_T *cctx, int with_white, int count);
 int generate_MULT_EXPR(cctx_T *cctx, isntype_T isn_type, int count);
+int generate_ECHOWINDOW(cctx_T *cctx, int count, long time);
 int generate_SOURCE(cctx_T *cctx, int sid);
 int generate_PUT(cctx_T *cctx, int regname, linenr_T lnum);
 int generate_EXEC_copy(cctx_T *cctx, isntype_T isntype, char_u *line);