When arc4random() is available, rk_random_init() does not have to
call arc4random_stir(). ac4random_stir() will be called as a result
of the first call to arc4random().
Change-Id: I6f4a3be7c39752746657945ed15896472908f889
In VC15 GetVersionEx has been deprecated. In order to continue to
support Win2K use the undeprecated VerifyVersionInfoW API
(available since Win2K).
Inline helper functions used in latest Win10 SDK to simplify code.
On Windows if the compiler and C RTL is >= 1400 then the rand_s()
function is available. rand_s() unlike rand() makes use of the
RtlGenRandom() API to produce a random number between 0 and UINT_MAX.
If rand_s() is not available or fails, fallback to rand().
One of the benefits of rand_s() is that no initialization is required
so it will provide random output even if rk_random_init() is not called.
Change-Id: I2768155de744bd49604fc8237728bb205d637f2a
