[patch] Implement std::pointer_safety etc.

[Jonathan Wakely <jwakely at redhat dot com>]

I forgot to add these (useless) functions that are required for full
C++11 conformance.

Tested powerpc64le-linux, committed to trunk.

I will probably backport these to 5.2 as well.

commit 95d0e38e22b85e6ffeea15678c6dce114c029be7
Author: Jonathan Wakely <jwakely@redhat.com>
Date:   Tue Jan 20 12:14:11 2015 +0000

    	* include/std/memory (pointer_safety, declare_reachable,
    	undeclare_reachable, declare_no_pointers, undeclare_no_pointers,
    	get_pointer_safety): Define.
    	* testsuite/20_util/pointer_safety/1.cc: New.

diff --git a/libstdc++-v3/include/std/memory b/libstdc++-v3/include/std/memory
index 4257394..3ed53b8 100644
--- a/libstdc++-v3/include/std/memory
+++ b/libstdc++-v3/include/std/memory
@@ -126,6 +126,26 @@ align(size_t __align, size_t __size, void*& __ptr, size_t& __space) noexcept
     }
 }
 
+// 20.7.4 [util.dynamic.safety], pointer safety
+
+enum class pointer_safety { relaxed, preferred, strict };
+
+inline void
+declare_reachable(void*) { }
+
+template <class T>
+  inline T*
+  undeclare_reachable(T* __p) { return __p; }
+
+inline void
+declare_no_pointers(char*, size_t) { }
+
+inline void
+undeclare_no_pointers(char*, size_t) { }
+
+inline pointer_safety
+get_pointer_safety() noexcept { return pointer_safety::relaxed; }
+
 _GLIBCXX_END_NAMESPACE_VERSION
 } // namespace
 #endif // _GLIBCXX_USE_C99_STDINT_TR1
diff --git a/libstdc++-v3/testsuite/20_util/pointer_safety/1.cc b/libstdc++-v3/testsuite/20_util/pointer_safety/1.cc
new file mode 100644
index 0000000..85793ff
--- /dev/null
+++ b/libstdc++-v3/testsuite/20_util/pointer_safety/1.cc
@@ -0,0 +1,43 @@
+// Copyright (C) 2015 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library.  This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+// { dg-options "-std=gnu++11" }
+
+#include <memory>
+#include <testsuite_hooks.h>
+
+void
+test01()
+{
+  char buf[8];
+
+  std::declare_reachable(buf);
+  char* p = std::undeclare_reachable(buf);
+  VERIFY( p == buf );
+
+  std::declare_no_pointers(p, sizeof(buf));
+  std::undeclare_no_pointers(p, sizeof(buf));
+
+  std::pointer_safety ps = std::get_pointer_safety();
+  VERIFY( ps == std::pointer_safety::relaxed );
+}
+
+int
+main()
+{
+  test01();
+}