fpu: Always decide no_signaling_nans() at runtime

fpu: Always decide no_signaling_nans() at runtime

Currently we have a compile-time shortcut where we
return false from no_signaling_nans() on everything except
Xtensa, because we know that's the only target that
might ever set status->no_signaling_nans.

Remove the ifdef, so we always look at the status flag;
this has no behavioural change, but will be necessary
if we want to build softfloat once for all targets.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20250224111524.1101196-10-peter.maydell@linaro.org
Message-id: 20250217125055.160887-8-peter.maydell@linaro.org