SystemStats::hasNeon on iOS/macOS

I think adding the following to CPUInformation::initialise() should mark hasNeon for macOS (DTK) and iOS. I have not tested it on hardware though, so it would be useful if anyone could?

   #ifdef JUCE_ARM
        unsigned int neon = 0;
        size_t len = sizeof (neon);
        if (sysctlbyname ("hw.optional.neon", &neon, &len, nullptr, 0) >= 0)
            hasNeon = neon != 0;

Great, I just found the following commit in SDL, maybe this function does not do as it says on iOS

So a better solution might be

   #if defined(JUCE_ARM) && (__ARM_ARCH >= 7)
    /* All Apple ARMv7 and up have NEON */
    hasNeon = true;