qPopulationCount uses unchecked SSE4 instructions with MSVC

With qtdeclarative/5.9 at b7090f1334ac7b8ad2548f084c749eda4fa82451 , Qt Core at f3b3e79feb64e57c2f0ab7030080920c338fd99e:

• Launch samegame, press Exit button
• Note crash

Note: Qt Creator 4.2 also crashes with a similar stack trace.

This is due to the use of qPopulationCount, which - when using MSVC intrinsics - expands to an SSE 4 instruction that requires CPUID checking at run-time. No such checking is done though.