Implement P0092R1 for C++1z

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@252195 91177308-0d34-0410-b5e6-96231b3b80d8

test/std/utilities/time/time.duration/time.duration.alg/abs.fail.cpp

@@ -0,0 +1,27 @@
+//===----------------------------------------------------------------------===//
+//
+//                     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.
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++03, c++11, c++14
+// <chrono>
+
+// ceil
+
+// template <class Rep, class Period>
+//   constexpr duration<Rep, Period> abs(duration<Rep, Period> d)
+
+// This function shall not participate in overload resolution unless numeric_limits<Rep>::is_signed is true.
+
+#include <chrono>
+
+typedef std::chrono::duration<unsigned> unsigned_secs;
+
+int main()
+{
+    std::chrono::abs(unsigned_secs(0));
+}