More fallout from global.cc namespace changes

[Benjamin Kosnik]

> GCC 3.2.X as built on freebsd4:
> 
> ; nm /usr/local/lib/libstdc++.so.5|grep _S_swap_lock
> 000541c8 d _ZNSt17_Swap_lock_structILi0EE12_S_swap_lockE

So if the stl_threads.h bits stay in namespace std for the patch on the
gcc-3_2-branch. Then?

-benjamin