Makes ldst_atomicity.c.inc almost target-independent, with the exception
of TARGET_PAGE_MASK, which will be addressed in a future patch.

Signed-off-by: Anton Johansson <anjo@rev.ng>
Message-Id: <20230912153428.17816-8-anjo@rev.ng>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>