Merge to upstream r225300.

Change-Id: I2b23715db9ac129ff80aa78ad5824db0a4d6fbb3

test/std/algorithms/alg.modifying.operations/alg.random.shuffle/random_shuffle.pass.cpp

@@ -0,0 +1,30 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// <algorithm>
+
+// template<RandomAccessIterator Iter>
+//   requires ShuffleIterator<Iter>
+//   void
+//   random_shuffle(Iter first, Iter last);
+
+#include <algorithm>
+#include <cassert>
+
+int main()
+{
+    int ia[] = {1, 2, 3, 4};
+    int ia1[] = {1, 4, 3, 2};
+    int ia2[] = {4, 1, 2, 3};
+    const unsigned sa = sizeof(ia)/sizeof(ia[0]);
+    std::random_shuffle(ia, ia+sa);
+    assert(std::equal(ia, ia+sa, ia1));
+    std::random_shuffle(ia, ia+sa);
+    assert(std::equal(ia, ia+sa, ia2));
+}

test/std/algorithms/alg.modifying.operations/alg.random.shuffle/random_shuffle_rand.pass.cpp

@@ -0,0 +1,37 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// <algorithm>
+
+// template<RandomAccessIterator Iter, Callable<auto, Iter::difference_type> Rand>
+//   requires ShuffleIterator<Iter>
+//         && Convertible<Rand::result_type, Iter::difference_type>
+//   void
+//   random_shuffle(Iter first, Iter last, Rand&& rand);
+
+#include <algorithm>
+#include <cassert>
+
+struct gen
+{
+    int operator()(int n)
+    {
+        return n-1;
+    }
+};
+
+int main()
+{
+    int ia[] = {1, 2, 3, 4};
+    int ia1[] = {4, 1, 2, 3};
+    const unsigned sa = sizeof(ia)/sizeof(ia[0]);
+    gen r;
+    std::random_shuffle(ia, ia+sa, r);
+    assert(std::equal(ia, ia+sa, ia1));
+}

test/std/algorithms/alg.modifying.operations/alg.random.shuffle/random_shuffle_urng.pass.cpp

@@ -0,0 +1,31 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// <algorithm>
+
+// template<class RandomAccessIterator, class UniformRandomNumberGenerator>
+//     void shuffle(RandomAccessIterator first, RandomAccessIterator last,
+//                  UniformRandomNumberGenerator& g);
+
+#include <algorithm>
+#include <random>
+#include <cassert>
+
+int main()
+{
+    int ia[] = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10};
+    int ia1[] = {2, 7, 1, 4, 3, 6, 5, 10, 9, 8};
+    int ia2[] = {1, 8, 3, 4, 6, 9, 5, 7, 2, 10};
+    const unsigned sa = sizeof(ia)/sizeof(ia[0]);
+    std::minstd_rand g;
+    std::shuffle(ia, ia+sa, g);
+    assert(std::equal(ia, ia+sa, ia1));
+    std::shuffle(ia, ia+sa, g);
+    assert(std::equal(ia, ia+sa, ia2));
+}