patch 9.1.0147: Cannot keep a buffer focused in a window

Problem:  Cannot keep a buffer focused in a window
          (Amit Levy)
Solution: Add the 'winfixbuf' window-local option
          (Colin Kennedy)

fixes:  #6445
closes: #13903

Signed-off-by: Colin Kennedy <colinvfx@gmail.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/src/proto/window.pro b/src/proto/window.pro
index e5c0396..9e66db5 100644
--- a/src/proto/window.pro
+++ b/src/proto/window.pro
@@ -1,4 +1,6 @@
 /* window.c */
+int check_can_set_curbuf_disabled(void);
+int check_can_set_curbuf_forceit(int forceit);
 int window_layout_locked(enum CMD_index cmd);
 win_T *prevwin_curwin(void);
 win_T *swbuf_goto_win_with_buf(buf_T *buf);