patch 8.2.4791: events triggered in different order when reusing buffer

Problem:    Autocmd events triggered in different order when reusing an empty
            buffer.
Solution:   Call buff_freeall() earlier. (Charlie Groves, closes #10198)

src/version.c

@@ -746,6 +746,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    4791,
 /**/
     4790,
 /**/