PATCH to libiberty: declare errno for portability

[Jeffrey A Law]

  In message <0007221653.AA03881@ivan.Harhan.ORG>you write:
  > Zack Weinberg <zack@wolery.cumb.org> wrote:
  > 
  > > What is the purpose of the "|| defined(_MSC_VER) && defined(_INC_ERRNO)" 
  > bit?
  > 
  > As I said, I just stole it from bfd in binutils.
Yea.  I went and found when the MSVC crud was added because it looked rather
bogus to me too.

Tue Feb 18 11:41:00 1997  Dawn Perchik  <dawn@cygnus.com>

        * sysdep.h: Don't define errno in MSVC if error.h is included.

Ugh.  Dawn should have done this with autoconf.  Ugh.
 

  > 2000-07-22  Michael Sokolov  <msokolov@ivan.Harhan.ORG>
  > 
  > 	* aclocal.m4 (libiberty_AC_DECLARE_ERRNO): New macro.
  > 	* configure.in (libiberty_AC_DECLARE_ERRNO): Add check.
  > 	* configure, config.in: Regenerate.
  > 	* pexecute.c, strtol.c, strtoul.c: Declare errno if necessary.
Thanks.  I'm installing this patch.

Note to the BFD folks, y'all might want to do something similar.

jeff