Added a make-dom function.
Added a make-dom function.

I was attempting to make a FIRST-CHILD pointer, but Z3 only handles
structural trees, so that isn't going to work. Maybe when I convert to
a finite-sort representation, this will go away.

uwplse/Cassius,uwplse/Cassius,uwplse/Cassius,uwplse/Cassius,uwplse/Cassius,uwplse/Cassius