patch 9.0.0350: :echowindow does not work in a compiled function
Problem: :echowindow does not work in a compiled function.
Solution: Handle the expression at compile time.
diff --git a/src/proto/popupwin.pro b/src/proto/popupwin.pro
index dcc14de..12be54f 100644
--- a/src/proto/popupwin.pro
+++ b/src/proto/popupwin.pro
@@ -67,6 +67,8 @@
void popup_show_message_win(void);
int popup_message_win_visible(void);
void popup_hide_message_win(void);
+void start_echowindow(void);
+void end_echowindow(void);
int popup_win_closed(win_T *win);
void popup_set_title(win_T *wp);
void popup_update_preview_title(void);