LynxOS support

LynxOS support

Hi Larry,

I've gone and ported your perl5.003 to LynxOS. I am attaching the
changes to make it work there. I am hoping you see fit to include them
in your next release. They are really quite minimal. I'm
really thankful the code is so portable. In summary the changes
affect three areas.

1) Configure support to have hints for LynxOS.

2) Our stdio under the covers has it spelled _fillbuf.

3) stat test fails because we don't have any setuid stuff in /usr/bin.
   It's all in /bin. Should be OK since all UNIX types I've seen have at
   the least su in /bin.

p5p-msgid: <m0vYEsY-0000IZC@kzinti.lynx.com>