Move test into test/std subdirectory.

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@224658 91177308-0d34-0410-b5e6-96231b3b80d8

test/std/thread/thread.mutex/thread.lock/thread.lock.shared/thread.lock.shared.mod/release.pass.cpp

@@ -0,0 +1,53 @@
+//===----------------------------------------------------------------------===//
+//
+//                     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: libcpp-has-no-threads
+
+// <shared_mutex>
+
+// template <class Mutex> class shared_lock;
+
+// mutex_type* release() noexcept;
+
+#include <shared_mutex>
+#include <cassert>
+
+#if _LIBCPP_STD_VER > 11
+
+struct mutex
+{
+    static int lock_count;
+    static int unlock_count;
+    void lock_shared() {++lock_count;}
+    void unlock_shared() {++unlock_count;}
+};
+
+int mutex::lock_count = 0;
+int mutex::unlock_count = 0;
+
+mutex m;
+
+#endif  // _LIBCPP_STD_VER > 11
+
+int main()
+{
+#if _LIBCPP_STD_VER > 11
+    std::shared_lock<mutex> lk(m);
+    assert(lk.mutex() == &m);
+    assert(lk.owns_lock() == true);
+    assert(mutex::lock_count == 1);
+    assert(mutex::unlock_count == 0);
+    assert(lk.release() == &m);
+    assert(lk.mutex() == nullptr);
+    assert(lk.owns_lock() == false);
+    assert(mutex::lock_count == 1);
+    assert(mutex::unlock_count == 0);
+    static_assert(noexcept(lk.release()), "release must be noexcept");
+#endif  // _LIBCPP_STD_VER > 11
+}