patch 8.2.4093: cached breakindent values not initialized properly

Problem:    Cached breakindent values not initialized properly.
Solution:   Initialize and cache formatlistpat. (Christian Brabandt,
            closes #9526, closes #9512)
diff --git a/src/proto/option.pro b/src/proto/option.pro
index 2390f58..a099624 100644
--- a/src/proto/option.pro
+++ b/src/proto/option.pro
@@ -73,6 +73,7 @@
 long get_scrolloff_value(void);
 long get_sidescrolloff_value(void);
 unsigned int get_bkc_value(buf_T *buf);
+char_u *get_flp_value(buf_T *buf);
 unsigned int get_ve_flags(void);
 char_u *get_showbreak_value(win_T *win);
 dict_T *get_winbuf_options(int bufopt);