{linux,bsd}-user: Introduce get_task_state()

{linux,bsd}-user: Introduce get_task_state()

A CPU's TaskState is stored in the CPUState's void *opaque field,
accessing which is somewhat awkward due to having to use a cast.
Introduce a wrapper and use it everywhere.

Suggested-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Reviewed-by: Warner Losh <imp@bsdimp.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20240219141628.246823-3-iii@linux.ibm.com>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20240305121005.3528075-4-alex.bennee@linaro.org>