[RFC] libstdc++/6720 and libstdc++/6671

[Benjamin Kosnik]

> This we have /already/ done! (see Phil's recent commit). But, 
> nonetheless, since it costs nothing, we can implement Zack's idea
> anyway...

I think this is a painless option that should be done.

For the rest of this....

I'm going to stay out of this morass. I still recovering from my last
bout with cpplib and the "C" compatibility headers to get to wrapped up
in the "ext" fiasco. 

-benjamin