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)
diff --git a/src/testdir/test_autocmd.vim b/src/testdir/test_autocmd.vim
index 724d073..fd36317 100644
--- a/src/testdir/test_autocmd.vim
+++ b/src/testdir/test_autocmd.vim
Binary files differ