Calls to `show` have been removed. To counter the loss of information,
the error positions have been improved and now correctly point to the
current selector instead of the entire select expression.
Change-Id: I4771fe874af1ac15828a9863550cd4369a8f0e94
The `show` functionality needs to be removed because it is deeply
flawed, and given that we already print position information in the
error message (which probably wasn't always the case in the past) the
assertion printing is redundant anyways.
Change-Id: I1f5e05ab73aaa0ec92994c2211463260fd374898