In e.g. `SELECT x AS y, y AS x FROM t ORDER BY x;`, the `x` in the
`ORDER BY` should reference t.y, which has been aliased as `x` for this
query. The same goes for GROUP BY, JOIN ON etc. but NOT for WHERE.
Previously we had wrong precedence in `bind_and_rewrite_expr`.
We had a bug where we were checking for duplicates in the DISTINCT
index based on both the result column count plus any ORDER BY columns
not present in the DISTINCT clause.
This is wrong, so fix it by only using the result columns for the
dedupe check.
Currently indexes are the bulk of the problem with `UPDATE` and
`DELETE`, while we work on fixing those it makes sense to disable
indexing since they are not stable. We want to try to make everything
else stable before we continue with indexing.
