re PR libstdc++/64658 (std::atomic_init() undefined)

	PR libstdc++/64658
	* include/std/atomic (atomic_init): Define.
	* testsuite/29_atomics/atomic/64658.cc: New.

From-SVN: r219886

libstdc++-v3/ChangeLog

+2015-01-20  Jonathan Wakely  <jwakely@redhat.com>
+
+	PR libstdc++/64658
+	* include/std/atomic (atomic_init): Define.
+	* testsuite/29_atomics/atomic/64658.cc: New.
+
 2015-01-19  Tim Shen  <timshen@google.com>
 
 	PR libstdc++/64649

libstdc++-v3/include/std/atomic

@@ -921,11 +921,13 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 
   template<typename _ITp>
     inline void
-    atomic_init(atomic<_ITp>* __a, _ITp __i) noexcept;
+    atomic_init(atomic<_ITp>* __a, _ITp __i) noexcept
+    { __a->store(__i, memory_order_relaxed); }
 
   template<typename _ITp>
     inline void
-    atomic_init(volatile atomic<_ITp>* __a, _ITp __i) noexcept;
+    atomic_init(volatile atomic<_ITp>* __a, _ITp __i) noexcept
+    { __a->store(__i, memory_order_relaxed); }
 
   template<typename _ITp>
     inline void

libstdc++-v3/testsuite/29_atomics/atomic/64658.cc

+// 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-require-atomic-builtins "" }
+// { dg-options "-std=gnu++11" }
+// { dg-do link }
+
+#include <atomic>
+
+int
+main()
+{
+  std::atomic<int> i;
+  atomic_init(&i, 0);
+}