CPS shrinking

[Stephen Weeks]

> I was working on eliminating extraneous compares, and I found the
> following:
...
> 	 val x_140 = MLton_eq (x_139, global_28)
>       in
> 	 case x_140 of
> 	   false => L_39 | true => L_39
>       end
...
> Anyways, I think the above could best be taken care of in CPS. 

Agreed.  I have patched my version of src/mlton/cps/shrink.fun to handle this
case.  I mistakenly thought it was, but there was an omission.  Let me know if
you see this any more, once you have grabbed the patch.