patch 8.1.1608: the evalfunc.c file is too big
Problem: The evalfunc.c file is too big.
Solution: Move sign functionality to sign.c.
diff --git a/src/proto/popupwin.pro b/src/proto/popupwin.pro
index 2f66946..7ac8612 100644
--- a/src/proto/popupwin.pro
+++ b/src/proto/popupwin.pro
@@ -2,6 +2,8 @@
int popup_on_border(win_T *wp, int row, int col);
void popup_start_drag(win_T *wp);
void popup_drag(win_T *wp);
+void popup_set_firstline(win_T *wp);
+void popup_handle_scrollbar_click(win_T *wp, int row, int col);
int popup_height(win_T *wp);
int popup_width(win_T *wp);
void popup_adjust_position(win_T *wp);