target/m68k: In frem helper, initialize local float_status from env->fp_status

target/m68k: In frem helper, initialize local float_status from env->fp_status

In the frem helper, we have a local float_status because we want to
execute the floatx80_div() with a custom rounding mode.  Instead of
zero-initializing the local float_status and then having to set it up
with the m68k standard behaviour (including the NaN propagation rule
and copying the rounding precision from env->fp_status), initialize
it as a complete copy of env->fp_status. This will avoid our having
to add new code in this function for every new config knob we add
to fp_status.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20241202131347.498124-31-peter.maydell@linaro.org