target/loongarch: Explicitly set 2-NaN propagation rule

target/loongarch: Explicitly set 2-NaN propagation rule

Set the 2-NaN propagation rule explicitly in the float_status word we
use.

(There are a couple of places in fpu_helper.c where we create a
dummy float_status word with "float_status *s = { };", but these
are only used for calling float*_is_quiet_nan() so it doesn't
matter that we don't set a 2-NaN propagation rule there.)

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20241025141254.2141506-6-peter.maydell@linaro.org