[v3] Add constexpr specifiers to std::shared_ptr, std::unique_ptr, etc

[Jonathan Wakely]

On 9 November 2010 03:28, H.J. Lu  wrote:
>
> This may have caused:
>
> http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46385

Apologies - I had another change in my tree which
I haven't committed yet and thought the weak_ptr test failure was
related to that.  Thanks Paolo for fixing it.