eliminated reliance on newlib malloc

[Conrad Scott]

Christopher Faylor wrote:
>
> I'm building a snapshot now.  I guess that will be the first
step
> in seeing just what I've broken.

If you're building on cygwin, I assume you'll have noticed that
sort(1) is now broken; it dies at malloc.cc:3644 in dlmalloc
(bytes=768).  (Sort is used in, at least, speclib, so that's why I
assume you would notice this problem if you build cygwin.)

On my machine this is an easy bug to reproduce: just running sort
with no arguments from the command line dies immediately.
Otherwise everything I'm using seems fine.

Cheers,

// Conrad