Merge to upstream r225300.

Change-Id: I2b23715db9ac129ff80aa78ad5824db0a4d6fbb3

test/std/numerics/rand/rand.eng/rand.eng.lcong/discard.pass.cpp

@@ -0,0 +1,73 @@
+//===----------------------------------------------------------------------===//
+//
+//                     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.
+//
+//===----------------------------------------------------------------------===//
+
+// <random>
+
+// template <class UIntType, UIntType a, UIntType c, UIntType m>
+//   class linear_congruential_engine;
+
+// void discard(unsigned long long z);
+
+#include <random>
+#include <cassert>
+
+template <class T>
+void
+rand0()
+{
+    typedef std::linear_congruential_engine<T, 16807, 0, 2147483647> E;
+    E e;
+    e.discard(9999);
+    assert(e() == 1043618065);
+}
+
+template <class T>
+void
+rand()
+{
+    typedef std::linear_congruential_engine<T, 48271, 0, 2147483647> E;
+    E e;
+    e.discard(9999);
+    assert(e() == 399268537);
+}
+
+template <class T>
+void
+other()
+{
+    typedef std::linear_congruential_engine<T, 48271, 123465789, 2147483647> E;
+    E e1;
+    E e2;
+    assert(e1 == e2);
+    e1.discard(1);
+    assert(e1 != e2);
+    e2();
+    assert(e1 == e2);
+    e1.discard(3);
+    assert(e1 != e2);
+    e2();
+    e2();
+    e2();
+    assert(e1 == e2);
+}
+
+int main()
+{
+    rand0<unsigned int>();
+    rand0<unsigned long>();
+    rand0<unsigned long long>();
+
+    rand<unsigned int>();
+    rand<unsigned long>();
+    rand<unsigned long long>();
+
+    other<unsigned int>();
+    other<unsigned long>();
+    other<unsigned long long>();
+}