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
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