[AURON #1924] [BUILD] Add -Xlint:_ to scala-maven-plugin and resolve related warnings

[1fanwang]

Which issue does this PR close?

Closes #1924. Sets up the next sibling under the [BUILD] epic #1869 (#1925) without changing its scope.

Rationale for this change

-Xlint:_ enables Scala's bundled lint checks, several of which catch real bug classes that the existing -Ywarn-unused + -Xfatal-warnings do not. This turns the flag on in both the base scala-maven-plugin config and the scala-2.13 profile, then resolves every warning it surfaces so the matrix build stays green.

What changes are included in this PR?

pom.xml -- add -Xlint:_ and -Wconf:cat=lint-inaccessible:s to both scala-maven-plugin arg lists. The lint-inaccessible silencer is commented inline: Auron implements Spark plugin SPIs (AppHistoryServerPlugin, the Shims trait, AuronRssShuffleWriterBase) whose contracts take private[spark] types (ElementTrackingStore, SparkUI, IndexShuffleBlockResolver, ShuffleWriteMetricsReporter). Exposing them in our overrides is required by Spark, not a defect, so silencing the category project-wide is cleaner than annotating every override site.

Source fixes for the warnings that are real bug classes (8 sites across 8 files):

• lint:adapted-args -- :+ ("k", v) on a Seq[(String, V)] was being silently auto-tupled. Made the Tuple2 explicit via ->. Files: ConvertToNativeBase, NativeBroadcastExchangeBase, NativeParquetInsertIntoHiveTableBase.

• lint:nonlocal-return -- return from inside a for { ... } / foreach { ... } body desugars to throw/catch via NonLocalReturnControl. Replaced with Iterable.exists in sparkver.matchVersion, and an early-exit while-loop over an iterator in SparkOnHeapSpillManager.spill.

• pattern shadowing (lint:type-parameter-shadow / pattern-shadow) -- pattern bindings reusing names from the enclosing scope. Renamed: case in: ... => -> case limited: ... => / case fileIn: ... => in AuronBlockStoreShuffleReaderBase; case expr => expr -> case other => other in SparkUDAFWrapperContext; case nativeXScanExec -> case scan in AuronEmptyNativeRddSuite.

Are there any user-facing changes?

No -- build-only.

How was this patch tested?

Local ./auron-build.sh --pre --sparkver <v> --scalaver <s> -DskipBuildNative -Dspotless.skip=true was green for:

• Spark 3.0 / Scala 2.12
• Spark 3.1 / Scala 2.12
• Spark 3.2 / Scala 2.12
• Spark 3.4 / Scala 2.12
• Spark 3.5 / Scala 2.12
• Spark 3.5 / Scala 2.13

Spark 3.3 / Scala 2.12 left for the matrix CI to cover (middle of the range, unlikely to surface different lint categories). Happy to iterate on any warning CI catches that I missed locally.

[Copilot]

Pull request overview

This PR tightens Scala compilation by enabling full Scala linting (-Xlint:_) in the Maven Scala compiler configuration, and updates a handful of Scala sources to eliminate the newly surfaced lint warnings while preserving existing runtime behavior.

Changes:

• Enable -Xlint:_ for Scala compilation (base + Scala 2.13 profile) and silence lint-inaccessible warnings project-wide via -Wconf.
• Replace non-local returns in Scala collection loops with exists / while early-exit patterns to avoid NonLocalReturnControl.
• Fix/avoid lint issues such as adapted-args tuple auto-tupled append and pattern binding shadowing.

Reviewed changes

Copilot reviewed 9 out of 9 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
spark-version-annotation-macros/src/main/scala/org/apache/auron/sparkver.scala	Replaces loop+return with exists to avoid non-local return lint.
spark-extension/src/main/scala/org/apache/spark/sql/execution/auron/shuffle/AuronBlockStoreShuffleReaderBase.scala	Renames pattern binders to avoid shadowing warnings in nested matches.
spark-extension/src/main/scala/org/apache/spark/sql/execution/auron/plan/NativeParquetInsertIntoHiveTableBase.scala	Makes appended metric tuples explicit using -> to avoid adapted-args lint.
spark-extension/src/main/scala/org/apache/spark/sql/execution/auron/plan/NativeBroadcastExchangeBase.scala	Makes appended metric tuples explicit using -> to avoid adapted-args lint.
spark-extension/src/main/scala/org/apache/spark/sql/execution/auron/plan/ConvertToNativeBase.scala	Makes appended metric tuple explicit using -> to avoid adapted-args lint.
spark-extension/src/main/scala/org/apache/spark/sql/auron/memory/SparkOnHeapSpillManager.scala	Removes non-local return from foreach by switching to an iterator while loop.
spark-extension/src/main/scala/org/apache/spark/sql/auron/SparkUDAFWrapperContext.scala	Renames pattern binder to avoid shadowing (case other => other).
spark-extension-shims-spark/src/test/scala/org/apache/auron/AuronEmptyNativeRddSuite.scala	Renames pattern binders in tests to avoid shadowing warnings.
pom.xml	Adds -Xlint:_ and suppresses lint-inaccessible warnings (base + Scala 2.13 profile).

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[yew1eb]

@1fanwang Thanks for the contribution! LGTM