Add inline to std::__invfwd

	PR libstdc++/59768
	* include/std/functional (__invfwd): Add inline specifier.

From-SVN: r231900

libstdc++-v3/ChangeLog

+2015-12-22  Jonathan Wakely  <jwakely@redhat.com>
+
+	PR libstdc++/59768
+	* include/std/functional (__invfwd): Add inline specifier.
+
 2015-12-21  Jonathan Wakely  <jwakely@redhat.com>
 
 	PR libstdc++/68982

libstdc++-v3/include/std/functional

@@ -207,7 +207,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
   // Used by __invoke_impl instead of std::forward<_Tp> so that a
   // reference_wrapper is converted to an lvalue-reference.
   template<typename _Tp>
-    typename _Unwrap<_Tp>::type
+    inline typename _Unwrap<_Tp>::type
     __invfwd(typename remove_reference<_Tp>::type& __t) noexcept
     { return _Unwrap<_Tp>::_S_fwd(__t); }