Environment defenitions

[Mark Kettenis]

Hi,

I raised this issue before, but I received no reaction.

Right now, `sysdeps/wordsize-32/bits/environments.h' leaves
`_XBS5_ILP32_OFFBIG' because 

   We optionally provide an environment with the above size but an
   64-bit side `off_t'.

(Oops there is a typo in thas comment).  However, right now this is
only true for the Linux port.  The Hurd doesn't support the
`_XBS5_ILP32_OFFBIG' environment, and I think in fact no other port does
right now.  Therefore I think that
`sysdeps/wordsize-32/bits/environments.h' should define
`_XBS5_ILP32_OFFBIG' to `-1' and the current file should be moved to
the linux specific directories.

If yu agree, I'm willing to provide a patch.  Otherwise, please think
of a better solution.

MARK