patch 8.1.1901: the +insert_expand feature is not always available

Problem:    The +insert_expand feature is not always available.
Solution:   Graduate the +insert_expand feature.
diff --git a/src/autocmd.c b/src/autocmd.c
index 640032b..8a6896b 100644
--- a/src/autocmd.c
+++ b/src/autocmd.c
@@ -1678,10 +1678,7 @@
 	    && has_cursorhold()
 	    && reg_recording == 0
 	    && typebuf.tb_len == 0
-#ifdef FEAT_INS_EXPAND
-	    && !ins_compl_active()
-#endif
-	    )
+	    && !ins_compl_active())
     {
 	state = get_real_state();
 	if (state == NORMAL_BUSY || (state & INSERT) != 0)
@@ -1726,7 +1723,6 @@
     return (first_autopat[(int)EVENT_TEXTCHANGEDI] != NULL);
 }
 
-#if defined(FEAT_INS_EXPAND) || defined(PROTO)
 /*
  * Return TRUE when there is a TextChangedP autocommand defined.
  */
@@ -1735,7 +1731,6 @@
 {
     return (first_autopat[(int)EVENT_TEXTCHANGEDP] != NULL);
 }
-#endif
 
 /*
  * Return TRUE when there is an InsertCharPre autocommand defined.
@@ -2044,9 +2039,7 @@
     if (!autocmd_busy)
     {
 	save_search_patterns();
-#ifdef FEAT_INS_EXPAND
 	if (!ins_compl_active())
-#endif
 	{
 	    saveRedobuff(&save_redo);
 	    did_save_redobuff = TRUE;