patch 8.2.4609: :unhide does not check for failing to close a window

Problem:    :unhide does not check for failing to close a window.
Solution:   When closing a window fails continue with the next one.  Do not
            try closing the autocmd window. (closes #9984)
diff --git a/src/testdir/test_autocmd.vim b/src/testdir/test_autocmd.vim
index 7be0c18..688508a 100644
--- a/src/testdir/test_autocmd.vim
+++ b/src/testdir/test_autocmd.vim
Binary files differ