Revert Add <optional>. Will recommit with better commit message

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@283978 91177308-0d34-0410-b5e6-96231b3b80d8

test/std/utilities/optional/optional.object/optional.object.observe/value_rvalue.pass.cpp

@@ -1,72 +0,0 @@
-//===----------------------------------------------------------------------===//
-//
-//                     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++98, c++03, c++11, c++14
-// <optional>
-
-// constexpr T& optional<T>::value() &&;
-
-#include <optional>
-#include <type_traits>
-#include <cassert>
-
-#include "test_macros.h"
-
-using std::optional;
-using std::bad_optional_access;
-
-struct X
-{
-    X() = default;
-    X(const X&) = delete;
-    constexpr int test() const & {return 3;}
-    int test() & {return 4;}
-    constexpr int test() const && {return 5;}
-    int test() && {return 6;}
-};
-
-struct Y
-{
-    constexpr int test() && {return 7;}
-};
-
-constexpr int
-test()
-{
-    optional<Y> opt{Y{}};
-    return std::move(opt).value().test();
-}
-
-int main()
-{
-    {
-        optional<X> opt; ((void)opt);
-        ASSERT_NOT_NOEXCEPT(std::move(opt).value());
-        ASSERT_SAME_TYPE(decltype(std::move(opt).value()), X&&);
-    }
-    {
-        optional<X> opt;
-        opt.emplace();
-        assert(std::move(opt).value().test() == 6);
-    }
-#ifndef TEST_HAS_NO_EXCEPTIONS
-    {
-        optional<X> opt;
-        try
-        {
-            std::move(opt).value();
-            assert(false);
-        }
-        catch (const bad_optional_access&)
-        {
-        }
-    }
-#endif
-    static_assert(test() == 7, "");
-}