[RFC] Large file iostreams

[Benjamin Kosnik]

>There is one more issue I would like input on before preparing a
>patch. Is config/os/gnu-linux/fpos.h needed? It doesn't seem to
>provide much over the generic version, it doesn't support stateT
>other than mbstate_t, and having two versions of the code makes
>testing harder.

You can revert this file and remove the resulting complexity.

This is not needed or really used at the moment. This was put in
with the attempt to use fgetpos/fsetpos, which didn't quite work for
reasons Paolo has already outlined. 

best,
benjamin