libiberty strsignal changes cause windows compilation breakage

[Eli Zaretskii]

> From: Chris Faylor <cgf@cygnus.com>
> Date: Wed, 31 May 2000 18:29:10 -0400
> 
> The strsignal file in libiberty was recently updated to include
> "string.h".  This has an unpleasant side effect on cygwin in that the
> declaration for strsignal in newlib's string.h is essentially this:
> 
> char *strsignal (int sig);
> 
> while the definition in strsignal.c is:
> 
> const char *strsignal (int sig)

If the Cygwin library has strsignal (which, as I understand, is the
reason for the prototype in string.h), then why is libiberty's
strsignal being linked in?  Shouldn't the configure script detect that
and refrain from using libiberty's strsignal?