new link errors with latest stdc++

[Paolo Carlini]

Kurt Kohler wrote:

>I hope someone can at least point me in the right direction to resolve
>this, I'm currently baffled.
>
This is unrelated to the shared_ptr changes.

Actually, it's a very bad C++ front-end bug, present in gcc4.0.2,
regression from gcc4.0.1. Basically, it renders the unordered_*
containers unusable in gcc4.0.2 :( It's already fixed for gcc4.0.3:

    http://gcc.gnu.org/bugzilla/show_bug.cgi?id=24389

Paolo.