enable n32 and n64, and move o32 into mips/mips32

[Roland McGrath]

> > I thought you were merging your working port into glibc, not
> > committing unfinished code.
> 
> I am.  But that's not to say it's finished.  The kernel is still
> undergoing ABI changes, and glibc has to be updated at the same time.

That is fine.  It doesn't have to be "finished" to go in.  But it does have
to be working for you.  And "it" means the current glibc plus your changes,
not the glibc of some time in the past plus some patches that haven't been
reconciled with the current code.  You do need to update your tree to the
current cvs and make sure that your build works before every time you
submit changes.