nullary _ffi's

[Stephen Weeks]

> > Thanks for the patch.  It fixed the problem with the regression failure
> > (cmdline).  Unfortunately, it introduced two new -native regression failures,
> > bytechar and string.  Do you see those failures as well?
> 
> I was able to recreate the failure and narrowed it down to a bug in the
> peephole optimization for signed division by a power of 2.  I'm including
> the updated x86-simplify.fun which should work with the version of the
> native backend that you have.

That fixed it.  Thanks.