libstdc++ new deque failures

[FX]

The patch below break bootstrap on darwin (https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63811):

> Fix std::deque move construction with non-equal allocators.
> 
> 	* include/bits/stl_deque.h (_Deque_base::_Deque_base(_Deque_base&&)):
> 	Dispatch according to whether allocators are always equal.
> 	(_Deque_base::_M_move_impl()): Implement move-from state.


In file included from /Users/fx/devel/gcc/ibin2/x86_64-apple-darwin14.0.0/libstdc++-v3/include/deque:64:0,
                 from /Users/fx/devel/gcc/trunk2/libstdc++-v3/include/precompiled/stdc++.h:67:
/Users/fx/devel/gcc/ibin2/x86_64-apple-darwin14.0.0/libstdc++-v3/include/bits/stl_deque.h: In member function ‘std::_Deque_base<_Tp, _Alloc>::_Deque_impl std::_Deque_base<_Tp, _Alloc>::_M_move_impl()’:
/Users/fx/devel/gcc/ibin2/x86_64-apple-darwin14.0.0/libstdc++-v3/include/bits/stl_deque.h:645:17: error: expected primary-expression before ‘__attribute’
  _Tp_alloc_type __attribute((__unused__)) {std::move(__alloc)};
                 ^
make[2]: *** [x86_64-apple-darwin14.0.0/bits/stdc++.h.gch/O2ggnu++0x.gch] Error 1