I've self-reviewed this patch again and I think it's now in a committable state. I'm wondering if we can mark it as 'Ready for Committer' now, or we need more review comments/feedbacks.
To recap, this patch postpones reparameterization of paths until createplan.c, which would help avoid building the reparameterized expressions we might not use. More importantly, it makes it possible to modify the expressions in RTEs (e.g. tablesample) and in RelOptInfos (e.g. baserestrictinfo) for reparameterization. Failing to do that can lead to executor crashes, wrong results, or planning errors, as we have already seen. Thanks Richard
