change expansion of ->i to make renaming work better in check syntax

Specifically, when expanding in the body of a dependent argument, put
the original variable for the dependened on field into that code, but
changing the expansion so that the binder becomes the original field's
x, not the x in the dependent declaration list.

This means that, for example, in this program:

(->i ([x any/c]
      [y (x) (begin x any/c)]
      [z (x) (begin x any/c)]) any)

the first x will be the binder and the other four now count as
bound occurrences.

Also, rip off Casey's redex check syntax tests to add tests

closes PR 13559
add a missing arg to jump-to-next-callback

closes PR 13560