Non-tuple exact and in lookups have specialized logic for subqueries that can
be adapted to properly assign select mask if unspecified and ensure the number
of involved members are matching on both side of the operator.
Thanks Lily Foote and Simon Charette for reviews and mentoring
this Google Summer of Code 2024 project.
Co-authored-by: Simon Charette <charette.s@gmail.com>
Co-authored-by: Lily Foote <code@lilyf.org>