patch 8.1.2044: no easy way to process postponed work

Problem:    No easy way to process postponed work. (Paul Jolly)
Solution:   Add the SafeState autocommand event.
diff --git a/src/proto/main.pro b/src/proto/main.pro
index 278d1ad..a6b9784 100644
--- a/src/proto/main.pro
+++ b/src/proto/main.pro
@@ -2,6 +2,9 @@
 int vim_main2(void);
 void common_init(mparm_T *paramp);
 int is_not_a_term(void);
+void may_trigger_safestate(int safe);
+void enter_unsafe_state(void);
+void leave_unsafe_state(void);
 void main_loop(int cmdwin, int noexmode);
 void getout_preserve_modified(int exitval);
 void getout(int exitval);