It seems on some compilers the test can pass but still give you
broken binaries.

Fixes: d2cd29e3
Fixes: https://bugs.launchpad.net/qemu/+bug/1871798


Cc: Bug 1871798 <1871798@bugs.launchpad.net>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Tested-by: Howard Spoelstra <hsp.cat7@gmail.com>
Tested-by: James Le Cuirot <chewi@aura-online.co.uk>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20200414200631.12799-9-alex.bennee@linaro.org>