target/s390x: Fix LAALG not updating cc_src

LAALG uses op_laa() and wout_addu64(). The latter expects cc_src to be
set, but the former does not do it. This can lead to assertion failures
if something sets cc_src to neither 0 nor 1 before.

Fix by introducing op_laa_addu64(), which sets cc_src, and using it for
LAALG.

Fixes: 4dba4d6f ("target/s390x: Use atomic operations for LOAD AND OP")
Cc: qemu-stable@nongnu.org
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-ID: <20231106093605.1349201-4-iii@linux.ibm.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>