target/i386/hvf: Use env_archcpu() in simulate_[rdmsr/wrmsr]()

target/i386/hvf: Use env_archcpu() in simulate_[rdmsr/wrmsr]()

When CPUArchState* is available (here CPUX86State*), we can
use the fast env_archcpu() macro to get ArchCPU* (here X86CPU*).
The QOM cast X86_CPU() macro will be slower when building with
--enable-qom-cast-debug.

Pass CPUX86State* as argument to simulate_rdmsr / simulate_wrmsr
instead of a CPUState* to avoid an extra cast.

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Roman Bolshakov <roman@roolebo.dev>
Tested-by: Roman Bolshakov <roman@roolebo.dev>
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Message-Id: <20231009110239.66778-7-philmd@linaro.org>