Add SQL null semantics to list_contains

[robert3005]

Add explicit SQL three-valued membership semantics to list_contains. A nonmatch against a list containing null yields null, so NOT IN does not admit that row. Regular semantics that flush null to false are still present

[codspeed]

Merging this PR will degrade performance by 5.18%

⚠️ Unknown Walltime execution environment detected

Using the Walltime instrument on standard Hosted Runners will lead to inconsistent data.

For the most accurate results, we recommend using CodSpeed Macro Runners: bare-metal machines fine-tuned for performance measurement consistency.

⚠️ Different runtime environments detected

Some benchmarks with significant performance changes were compared across different runtime environments,
which may affect the accuracy of the results.

Open the report in CodSpeed to investigate

⚡ 1 improved benchmark
❌ 2 regressed benchmarks
✅ 2059 untouched benchmarks
⏩ 503 skipped benchmarks¹

Warning

Please fix the performance issues or acknowledge them on CodSpeed.

Performance Changes

	Mode	Benchmark	BASE	HEAD	Efficiency
❌	Simulation	sum_i64	193.3 µs	224.6 µs	-13.94%
❌	Simulation	sum_v2_i64	193.8 µs	225 µs	-13.85%
⚡	WallTime	dict_canonicalize_gt_u8_neon[1000000]	561.6 µs	488.4 µs	+14.98%

Tip

Investigate this regression by commenting @codspeedbot fix this regression on this PR, or directly use the CodSpeed MCP with your agent.

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_{Comparing rk/list-contains-sql-null-semantics (de591fc) with develop (52e6407)}

Footnotes

1. 503 benchmarks were skipped, so the baseline results were used instead. If they were deleted from the codebase, click here and archive them to remove them from the performance reports. ↩