These are the changes to libstdc++ to make use of the new atomics.  I 
changed the files to use the new atomics, and bkoz did a shuffling of 
the include file layout to better suit the new c++ approach.

previously, libstdc++ provided a locked implementation in atomic_0.h 
with the theory that eventually it would be used.  The new scheme 
involves leaving non-lock-free implementations to an external library. 
This involved removing the old lock implementation and restructuring 
things now that multiple implementation dont have to be supported.   SO 
a lot fo this is churn... 2 include files deleted and one merged into 
another one..