softfloat: add NO_SIGNALING_NANS

Architectures that don't have signaling NaNs can define
NO_SIGNALING_NANS, it will make float*_is_quiet_nan return 1 for any NaN
and float*_is_signaling_nan always return 0.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
diff --git a/fpu/softfloat.h b/fpu/softfloat.h
index 2860ca0..d8999b3 100644
--- a/fpu/softfloat.h
+++ b/fpu/softfloat.h
@@ -251,6 +251,11 @@
 int float16_is_signaling_nan( float16 );
 float16 float16_maybe_silence_nan( float16 );
 
+INLINE int float16_is_any_nan(float16 a)
+{
+    return ((float16_val(a) & ~0x8000) > 0x7c00);
+}
+
 /*----------------------------------------------------------------------------
 | The pattern for a default generated half-precision NaN.
 *----------------------------------------------------------------------------*/