CryptGenRandom is deprecated (Windows)

https://docs.microsoft.com/en-us/windows/win32/api/wincrypt/nf-wincrypt-cryptgenrandom

The folks at [crossguid](https://github.com/graeme-hill/crossguid/blob/master/src/guid.cpp)  are using [CoCreateGuid](https://docs.microsoft.com/en-us/windows/win32/api/combaseapi/nf-combaseapi-cocreateguid), so maybe that's a good alternative. I have no idea really, but I thought it might be worth raising.