IN LIST: reinterpret small-width types for bitmap filters

[geoffreyclaude]

Which issue does this PR close?

• Part of Further improve performance of IN list evaluation #19241.
• Based on main after IN LIST: unify bitmap filter implementations #23035.
• Next in stack: IN LIST: add branchless filter for small primitive lists #23014.
• Extracted from Optimize IN performance with specialized implementations #19390.

Rationale for this change

#23011 and #23012 add bitmap lookups for unsigned 1-byte and 2-byte integers, and #23035 unifies those concrete filters behind one shared bitmap implementation. This PR lets signed primitive types with the same byte width reuse those bitmaps without copying values.

For Int8 and Int16, the IN-list values and input values still have the same logical type. The optimization only changes the internal representation used by the lookup filter: Int8 is viewed through the UInt8 bitmap representation, and Int16 is viewed through the UInt16 bitmap representation.

This is a zero-copy view of the same bytes, not a numeric cast. For example, an Int8 value such as -1 is inserted and probed through the same one-byte bit pattern. The wrapper also keeps the original array type, so a filter built from Int8 is probed with Int8 values, not arbitrary same-width arrays.

What changes are included in this PR?

• Adds a helper that views a primitive Arrow array as another primitive type with the same width.
• Makes the helper slice-aware, so sliced Arrow arrays still start at the correct logical offset.
• Wraps bitmap filters so signed 1-byte and 2-byte primitive arrays can reuse the unsigned bitmap storage.
• Validates source width before constructing a reinterpreted bitmap filter.
• Preserves the original array type on the wrapper and validates it again before probing.
• Adds focused coverage for signed boundary values, sliced arrays, and NOT IN.

Are these changes tested?

Yes.

• cargo fmt --all -- --check
• cargo test -p datafusion-physical-expr expressions::in_list --lib
• cargo clippy --all-targets --all-features -- -D warnings

Are there any user-facing changes?

No. This is an internal performance optimization only.

Local benchmark snapshot

Benchmark command:

cargo bench -p datafusion-physical-expr --profile release-nonlto --bench in_list_strategy -- --save-baseline <name>

Method: compare adjacent saved baselines using raw Criterion sample minima (min(time / iters)). Lower is better; changes within +/-5% are treated as noise. These numbers were not rerun after splitting the behavior-preserving bitmap unification into #23035.

Compared baselines: #23035 -> #23013

Relevant scope: signed 16-bit reinterpretation rows.

Summary: 6 relevant rows, 6 faster, 0 slower, 0 within +/-5%.

Benchmark	Before	After	Change
narrow_integer/i16/list=256/match=0%	19.15 us	4.00 us	-79.1% (4.79x faster)
narrow_integer/i16/list=256/match=50%	31.32 us	4.00 us	-87.2% (7.82x faster)
narrow_integer/i16/list=4/match=0%	16.79 us	4.01 us	-76.1% (4.18x faster)
narrow_integer/i16/list=4/match=50%	34.80 us	4.01 us	-88.5% (8.69x faster)
narrow_integer/i16/list=64/match=0%	19.21 us	4.11 us	-78.6% (4.68x faster)
narrow_integer/i16/list=64/match=50%	34.72 us	4.01 us	-88.5% (8.66x faster)