Add a small test to prevent regressions.

Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-ID: <20231106093605.1349201-3-iii@linux.ibm.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>