patch 9.0.0036: 'fillchars' cannot have window-local values

Problem:    'fillchars' cannot have window-local values.
Solution:   Make 'fillchars' global-local. (closes #5206)
diff --git a/src/proto/screen.pro b/src/proto/screen.pro
index 0ee1b5e..de42c43 100644
--- a/src/proto/screen.pro
+++ b/src/proto/screen.pro
@@ -7,7 +7,7 @@
 size_t fill_foldcolumn(char_u *p, win_T *wp, int closed, linenr_T lnum);
 int screen_get_current_line_off(void);
 void reset_screen_attr(void);
-void screen_line(int row, int coloff, int endcol, int clear_width, int flags);
+void screen_line(win_T *wp, int row, int coloff, int endcol, int clear_width, int flags);
 void rl_mirror(char_u *str);
 void draw_vsep_win(win_T *wp, int row);
 void win_redr_status_matches(expand_T *xp, int num_matches, char_u **matches, int match, int showtail);
@@ -48,7 +48,7 @@
 void draw_tabline(void);
 void get_trans_bufname(buf_T *buf);
 int fillchar_status(int *attr, win_T *wp);
-int fillchar_vsep(int *attr);
+int fillchar_vsep(int *attr, win_T *wp);
 int redrawing(void);
 int messaging(void);
 void comp_col(void);