target/arm: Introduce finalize_memop_{atom,pair}

target/arm: Introduce finalize_memop_{atom,pair}

Let finalize_memop_atom be the new basic function, with
finalize_memop and finalize_memop_pair testing FEAT_LSE2
to apply the appropriate atomicity.

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20230530191438.411344-4-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>