re PR target/64368 (Several libstdc++ test failures on non-linux platforms after r218964.)

	PR libstdc++/64368
	* include/std/shared_mutex (shared_timed_mutex::try_lock_for,
	shared_timed_mutex::try_lock_until): Only define when POSIX thread
	timeouts option is supported.
	(shared_timed_mutex::try_shared_lock_for,
	shared_timed_mutex::try_shared_lock_until): Likewise.

From-SVN: r220161

libstdc++-v3/ChangeLog

+2015-01-27  Jonathan Wakely  <jwakely@redhat.com>
+
+	PR libstdc++/64368
+	* include/std/shared_mutex (shared_timed_mutex::try_lock_for,
+	shared_timed_mutex::try_lock_until): Only define when POSIX thread
+	timeouts option is supported.
+	(shared_timed_mutex::try_shared_lock_for,
+	shared_timed_mutex::try_shared_lock_until): Likewise.
+
 2015-01-26  Jonathan Wakely  <jwakely@redhat.com>
 
 	PR libstdc++/64368

libstdc++-v3/include/std/shared_mutex

@@ -108,6 +108,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
       return true;
     }
 
+#if _GTHREAD_USE_MUTEX_TIMEDLOCK
     template<typename _Rep, typename _Period>
       bool
       try_lock_for(const chrono::duration<_Rep, _Period>& __rel_time)
@@ -149,6 +150,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 	const auto __s_atime = __s_entry + __delta;
 	return try_lock_until(__s_atime);
       }
+#endif
 
     void
     unlock()
@@ -186,6 +188,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
       return true;
     }
 
+#if _GTHREAD_USE_MUTEX_TIMEDLOCK
     template<typename _Rep, typename _Period>
       bool
       try_lock_shared_for(const chrono::duration<_Rep, _Period>& __rel_time)
@@ -230,6 +233,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 	const auto __s_atime = __s_entry + __delta;
 	return try_lock_shared_until(__s_atime);
       }
+#endif
 
     void
     unlock_shared()