[MLton] Cygwin->Mingw32: patch + future

[Matthew Fluet]

> > I propose to remove all the text/binary toggles out of the
> > SML library and put all MLton filedescs in binary mode. Then add translation
> > at the level of TextIO. More work to be done in the MLton basis library,
> > true. However, this will probably be more portable in the long run and
> > makes several otherwise impossible problems solvable
> ...
> > Make both TextIO.stdin and BinIO.stdin point to the same underlying buffer
> > and bingo, it finally works the way C should have. If you combine this with
> > your above suggestion of returning the same stream, one can even guarantee
> > that reads/writes to the same fd are not order-mangled by the buffers.
>
> This seems like a fine idea to me.  I am interested to hear others'
> thoughts though.

I think it is an o.k. idea, but if we are doing more work in the
basis library, will that slow down TextIO.  Maybe not on Unix, but
possibly under Windows.