Fix ilogbl crash and fetestexcept build if _MSC_VER>=1800 (#238)
Fix ilogbl crash and fetestexcept build if _MSC_VER>=1800 (#238)

FP_ILOGB0, FP_ILOGBNAN, ilogbm, ilogbf, ilogbl, fetestexcept and
feclearexcept are supported in Visual Studio 2013.
KhronosGroup/OpenCL-CTS,KhronosGroup/OpenCL-CTS,KhronosGroup/OpenCL-CTS,KhronosGroup/OpenCL-CTS