Move Source/WTF/wtf to Source/wtf

Source/WTF/wtf/NullPtr.h

-/*
-
-Copyright (C) 2010 Apple Inc. All rights reserved.
-
-Redistribution and use in source and binary forms, with or without
-modification, are permitted provided that the following conditions
-are met:
-1.  Redistributions of source code must retain the above copyright
-    notice, this list of conditions and the following disclaimer.
-2.  Redistributions in binary form must reproduce the above copyright
-    notice, this list of conditions and the following disclaimer in the
-    documentation and/or other materials provided with the distribution.
-
-THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS'' AND ANY
-EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
-WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
-DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS BE LIABLE FOR ANY
-DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
-(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
-LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
-ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
-SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-
-*/
-
-#ifndef NullPtr_h
-#define NullPtr_h
-
-// For compilers and standard libraries that do not yet include it, this adds the
-// nullptr_t type and nullptr object. They are defined in the same namespaces they
-// would be in compiler and library that had the support.
-
-#include <ciso646>
-
-#if COMPILER_SUPPORTS(CXX_NULLPTR) || defined(_LIBCPP_VERSION)
-
-#include <cstddef>
-
-// libstdc++ supports nullptr_t starting with gcc 4.6.
-#if defined(__GLIBCXX__) && __GLIBCXX__ < 20110325
-namespace std {
-typedef decltype(nullptr) nullptr_t;
-}
-#endif
-
-#else
-
-namespace std {
-class WTF_EXPORT_PRIVATE nullptr_t { };
-}
-extern WTF_EXPORT_PRIVATE std::nullptr_t nullptr;
-
-#endif
-
-#endif