[libstdc++-v3] Remove std::construct and std::destroy

[Benjamin Kosnik]

Hey Stephen. This is in, thanks.

> Bootstrapped on an i686-pc-linux-gnu system, no regressions.  Targetted at the
> trunk but is good for the 3.01 branch, too.

I just checked it in to the trunk. I'm uncertain what to do with patches 
that remove functions from std:: or otherwise change the library 
significantly. (Say this patch, or the iterator work.) Right now I'm now 
checking them into the branch, although this might be a mistake.

-benjamin