`given ... with` or `given ... = new { ... }` kinds of definitions now follow
the old rules. This allows recursive `given...with` definitions as they are
found in protoQuill.

We still have the old check in a later phase against directly recursive methods.
Of the three loops in the original i15474 we now detect #2 and #3 with new new
restrictions. #1 slips through since it is a loop involving a `given...with` instance
of `Conversion`, but is caught later with the recursive method check.

Previously tests #1 and #3 were detected with the recursive methods check and #2 slipped
through altogether.

The new rules are enough for defining simple givens with `=` without fear of looping.