Fix query optimization for semijoins#4287
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Description of Changes
Fixes a planner bug where certain join queries could fail with:
The reason was that in the process of rewriting the query with semijoins, the fallback branch of the optimization rule didn't track the dependencies of the join correctly. In particular it didn't mark the LHS table in the join condition as a dependency when recursing into the LHS of the join tree. This led to the table being projected out or dropped in the LHS subtree while still being referenced by the root of the subtree.
This only happened for bridge tables (tables used to link or bridge other tables in the join, but whose columns are not referenced in the final output). If the table was referenced in the output, it would be included in the list of dependencies from the start and so this bug would not manifest.
API and ABI breaking changes
None
Expected complexity level and risk
1
Testing
Added a sql execution test