New back end ia16: 16-bit Intel x86

[Richard Kenner]

> I think that it would be much better to have 16-bit support as part of
> the current x86 back end, both from our point of view as developers
> (because there is a fair amount of commonality) and from the point of
> view of users (because having different compilers for the same CPU is
> odd, and some developers will want to develop both 16-bit and 32-bit code).

I agree completely.