`opus_cpu_feature_check` doesn't check XState

[MichalPetryka]

opus_cpu_feature_check only checks cpuid today and not xgetbv which can cause crashes when AVX is disabled there.

The code should also check if it's enabled using GetEnabledXStateFeatures on Windows and _xgetbv otherwise.

opus/celt/x86/x86cpu.c

Lines 111 to 138 in f18e26e

	static void opus_cpu_feature_check(CPU_Feature *cpu_feature)
	{
	unsigned int info[4];
	unsigned int nIds = 0;
	cpuid(info, 0);
	nIds = info[0];
	if (nIds >= 1){
	cpuid(info, 1);
	cpu_feature->HW_SSE = (info[3] & (1 << 25)) != 0;
	cpu_feature->HW_SSE2 = (info[3] & (1 << 26)) != 0;
	cpu_feature->HW_SSE41 = (info[2] & (1 << 19)) != 0;
	cpu_feature->HW_AVX2 = (info[2] & (1 << 28)) != 0 && (info[2] & (1 << 12)) != 0;
	if (cpu_feature->HW_AVX2 && nIds >= 7) {
	cpuid(info, 7);
	cpu_feature->HW_AVX2 = cpu_feature->HW_AVX2 && (info[1] & (1 << 5)) != 0;
	} else {
	cpu_feature->HW_AVX2 = 0;
	}
	}
	else {
	cpu_feature->HW_SSE = 0;
	cpu_feature->HW_SSE2 = 0;
	cpu_feature->HW_SSE41 = 0;
	cpu_feature->HW_AVX2 = 0;
	}
	}