[SPARK-56909][SQL] Simplify Cast to int/long codegen under ANSI mode

[gengliangwang]

What changes were proposed in this pull request?

Introduce CastUtils.java and use it from Cast.scala to collapse the multi-line ANSI overflow-check codegen for casts that target int and long into one-line static-method calls. Source and target DataType constants used in the overflow error message live as private static final fields on the helper class, so the happy path performs no per-row references[] lookups.

Helpers added:

• longToIntExact(long) for narrowing long -> int.
• floatToIntExact(float), doubleToIntExact(double) for fractional -> int.
• floatToLongExact(float), doubleToLongExact(double) for fractional -> long.

Cast.scala changes:

• castIntegralTypeToIntegralTypeExactCode and castFractionToIntegralTypeCode dispatch on the target type: int (and long for the fraction case) emit a CastUtils.<...>Exact call; byte/short targets keep the inline body (refactored in SPARK-56910).
• Eval paths for castToInt add ANSI LongType / FloatType / DoubleType cases, and castToLong adds FloatType / DoubleType cases, both delegating to the new helpers.

Why are the changes needed?

Part of SPARK-56908 (umbrella). The current ANSI cast codegen emits 5-line inline overflow blocks per call site. Multiplied across the many cast paths in a TPC-DS plan, this contributes meaningfully to the generated source size and to Janino compile time, and pushes whole-stage methods closer to the 64KB JVM method limit.

Does this PR introduce any user-facing change?

No. The compiled behavior is identical; only the emitted Java source text changes.

How was this patch tested?

build/sbt "catalyst/testOnly *CastSuite *CastWithAnsiOnSuite *CastWithAnsiOffSuite *AnsiCastSuite *TryCastSuite"

All cast suites 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.