added check for ANGLE_PLATFORM_WINRT to enable desktop compilation
added check for ANGLE_PLATFORM_WINRT to enable desktop compilation

MSOpenTech/angle-win8.0,MSOpenTech/angle-win8.0,MSOpenTech/angle-win8.0,stammen/angleproject,MSOpenTech/angle-win8.0,stammen/angleproject,stammen/angleproject,stammen/angleproject