[PATCH] Implement std::experimental::sample

[Marshall Clow]

- SampleIterator shall meet the additional requirements of a RandomAccessIterator type

unless PopulationIterator meets the additional requirements of a ForwardIterator
type.

So if I call `sample(InputIterator, InputIterator, ForwardIterator, 1, rnd)`, I should get a compile error.


http://reviews.llvm.org/D9044

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