[SPARK-56913][SQL] Simplify BinaryArithmetic byte/short codegen under ANSI mode

[gengliangwang]

Title: [SPARK-56913][SQL] Refactor BinaryArithmetic byte/short codegen under ANSI mode
Base: master (independent)
Head: gengliangwang:SPARK-56913-arithmetic-byte-short

What changes were proposed in this pull request?

Introduce ArithmeticUtils.java with six static helpers (byteAddExact, byteSubtractExact, byteMultiplyExact, shortAddExact, shortSubtractExact, shortMultiplyExact) and use them from BinaryArithmetic.doGenCode and from Add / Subtract / Multiply.nullSafeEval.

The Byte/Short ANSI overflow-check branch of BinaryArithmetic.doGenCode previously emitted ~7 lines per call site (int tmpResult + overflow check + cast back). After this PR it emits a single ArithmeticUtils.<type><Op>Exact(...) call.

The eval-path counterparts for Add/Subtract/Multiply also delegate to the helpers under ANSI mode, replacing the previous fall-through to numeric.plus/minus/times (which threw a generic ArithmeticException) -- the eval path now produces the same SQL-formatted BINARY_ARITHMETIC_OVERFLOW error as the codegen path.

Primitive int/long/float/double branches are intentionally left inline (single bytecode op; routing through a static method would be a runtime regression).

Why are the changes needed?

Part of SPARK-56908 (umbrella). The Byte/Short ANSI branch is the largest single inline body in BinaryArithmetic.doGenCode.

Does this PR introduce any user-facing change?

No. Compiled behavior is identical; the eval path now produces a SQL-formatted overflow error matching the codegen path (the previous generic ArithmeticException was an inconsistency).

How was this patch tested?

build/sbt "catalyst/testOnly *ArithmeticExpressionSuite"

35/35 pass.

Was this patch authored or co-authored using generative AI tooling?

Generated-by: Cursor 1.x

[gengliangwang]

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Stack overview (SPARK-56908 umbrella)

This PR is part of a stack of 8 PRs against SPARK-56908. Order:

1. [SPARK-56909][SQL] Simplify Cast to int/long codegen under ANSI mode #55934 — [SPARK-56909][SQL] Simplify Cast to int/long codegen under ANSI mode (this stack base)
2. [SPARK-56910][SQL] Simplify Cast to byte/short codegen under ANSI mode #55935 — [SPARK-56910][SQL] Simplify Cast to byte/short codegen under ANSI mode
3. [SPARK-56911][SQL] Simplify Cast to decimal codegen under ANSI mode #55936 — [SPARK-56911][SQL] Simplify Cast to decimal codegen under ANSI mode
4. [SPARK-56912][SQL] Simplify Cast to boolean codegen under ANSI mode #55937 — [SPARK-56912][SQL] Simplify Cast to boolean codegen under ANSI mode
5. [SPARK-56914][SQL] Simplify decimal arithmetic codegen under ANSI mode #55939 — [SPARK-56914][SQL] Simplify decimal arithmetic codegen under ANSI mode (depends on [SPARK-56911][SQL] Simplify Cast to decimal codegen under ANSI mode #55936)
6. [SPARK-56913][SQL] Simplify BinaryArithmetic byte/short codegen under ANSI mode #55938 — [SPARK-56913][SQL] Simplify BinaryArithmetic byte/short codegen under ANSI mode (independent)
7. [SPARK-56915][SQL] Simplify MakeDate/MakeInterval codegen under ANSI mode #55940 — [SPARK-56915][SQL] Simplify MakeDate/MakeInterval codegen under ANSI mode (independent)
8. [SPARK-56916][SQL] Simplify ElementAt array codegen under ANSI mode #55941 — [SPARK-56916][SQL] Simplify ElementAt array codegen under ANSI mode (independent)

PRs 1-4 are linearly stacked on each other (each branch is based on the previous one). PR 5 (decimal arithmetic) is stacked on top of PR 3 (cast decimal) since it uses CastUtils.changePrecisionExact. PRs 6, 7, 8 branch off master independently.