Retain NaN bits in fp16/fp32 conversions.
Retain NaN bits in fp16/fp32 conversions.

This matches PSP behavior better.

hrydgard/native,zhykzhykzhyk/ppsspp-native,libretro/ppsspp-native,libretro/ppsspp-native,hrydgard/native,hrydgard/native,zhykzhykzhyk/ppsspp-native,libretro/ppsspp-native,zhykzhykzhyk/ppsspp-native,hrydgard/native,zhykzhykzhyk/ppsspp-native,libretro/ppsspp-native