[PATCH] export asprintf and friends

[Charles Wilson]

The newlib patch has been applied, so this change to winsup -- if 
desired -- can be committed.

Charles Wilson wrote:
> This patch assumes that the asprintf.c change I submitted to newlib is 
> also applied.  (And no, it doesn't fix the problem I was having with 
> glib and the printf functions, but I noticed this oversight -- and the 
> newlib typo -- while doing that investigation)
> 
> 2003-01-01  Charles Wilson  <cwilson@ece.gatech.edu>
> 
>     * cygwin.din: add asprintf and vasprintf, as
>     well as the reentrant versions and underscore
>     variants.