Second try at getting noexcept on move and swap for deque. I changed...

Second try at getting noexcept on move and swap for deque.  I changed std::alloctor to propagate_on_container_move_assignment so as to make deque<T> move assignment noexcept.  What we really need is a compile-time switch that says an allocator always compares equal.

llvm-svn: 132490