[SPARK-33921][BUILD] Upgrade Scala version to 2.12.12

dev/deps/spark-deps-hadoop-2.7-hive-2.3

@@ -212,10 +212,10 @@ protobuf-java/2.5.0//protobuf-java-2.5.0.jar
 py4j/0.10.9//py4j-0.10.9.jar
 pyrolite/4.30//pyrolite-4.30.jar
 scala-collection-compat_2.12/2.1.1//scala-collection-compat_2.12-2.1.1.jar
-scala-compiler/2.12.10//scala-compiler-2.12.10.jar
-scala-library/2.12.10//scala-library-2.12.10.jar
+scala-compiler/2.12.12//scala-compiler-2.12.12.jar
+scala-library/2.12.12//scala-library-2.12.12.jar
 scala-parser-combinators_2.12/1.1.2//scala-parser-combinators_2.12-1.1.2.jar
-scala-reflect/2.12.10//scala-reflect-2.12.10.jar
+scala-reflect/2.12.12//scala-reflect-2.12.12.jar
 scala-xml_2.12/1.2.0//scala-xml_2.12-1.2.0.jar
 shapeless_2.12/2.3.3//shapeless_2.12-2.3.3.jar
 shims/0.9.0//shims-0.9.0.jar

dev/deps/spark-deps-hadoop-3.2-hive-2.3

@@ -228,10 +228,10 @@ py4j/0.10.9//py4j-0.10.9.jar
 pyrolite/4.30//pyrolite-4.30.jar
 re2j/1.1//re2j-1.1.jar
 scala-collection-compat_2.12/2.1.1//scala-collection-compat_2.12-2.1.1.jar
-scala-compiler/2.12.10//scala-compiler-2.12.10.jar
-scala-library/2.12.10//scala-library-2.12.10.jar
+scala-compiler/2.12.12//scala-compiler-2.12.12.jar
+scala-library/2.12.12//scala-library-2.12.12.jar
 scala-parser-combinators_2.12/1.1.2//scala-parser-combinators_2.12-1.1.2.jar
-scala-reflect/2.12.10//scala-reflect-2.12.10.jar
+scala-reflect/2.12.12//scala-reflect-2.12.12.jar
 scala-xml_2.12/1.2.0//scala-xml_2.12-1.2.0.jar
 shapeless_2.12/2.3.3//shapeless_2.12-2.3.3.jar
 shims/0.9.0//shims-0.9.0.jar

docs/_config.yml

@@ -22,7 +22,7 @@ include:
 SPARK_VERSION: 3.2.0-SNAPSHOT
 SPARK_VERSION_SHORT: 3.2.0
 SCALA_BINARY_VERSION: "2.12"
-SCALA_VERSION: "2.12.10"
+SCALA_VERSION: "2.12.12"
 MESOS_VERSION: 1.0.0
 SPARK_ISSUE_TRACKER_URL: https://issues.apache.org/jira/browse/SPARK
 SPARK_GITHUB_URL: https://github.com/apache/spark

pom.xml

@@ -162,7 +162,7 @@
     <commons.math3.version>3.4.1</commons.math3.version>
     <!-- managed up from 3.2.1 for SPARK-11652 -->
     <commons.collections.version>3.2.2</commons.collections.version>
-    <scala.version>2.12.10</scala.version>
+    <scala.version>2.12.12</scala.version>
     <scala.binary.version>2.12</scala.binary.version>
     <scalatest-maven-plugin.version>2.0.0</scalatest-maven-plugin.version>
     <scalafmt.parameters>--test</scalafmt.parameters>

project/SparkBuild.scala

@@ -200,13 +200,12 @@ object SparkBuild extends PomBuild {
   // Silencer: Scala compiler plugin for warning suppression
   // Aim: enable fatal warnings, but suppress ones related to using of deprecated APIs
   // depends on scala version:
-  // <2.13 - silencer 1.6.0 and compiler settings to enable fatal warnings
-  // 2.13.0,2.13.1 - silencer 1.7.1 and compiler settings to enable fatal warnings
+  // <2.13.1 - silencer 1.7.1 and compiler settings to enable fatal warnings
   // 2.13.2+ - no silencer and configured warnings to achieve the same
   lazy val compilerWarningSettings: Seq[sbt.Def.Setting[_]] = Seq(
     libraryDependencies ++= {
       if (VersionNumber(scalaVersion.value).matchesSemVer(SemanticSelector("<2.13.2"))) {
-        val silencerVersion = if (scalaBinaryVersion.value == "2.13") "1.7.1" else "1.6.0"
+        val silencerVersion = "1.7.1"
         Seq(
           "org.scala-lang.modules" %% "scala-collection-compat" % "2.2.0",
           compilerPlugin("com.github.ghik" % "silencer-plugin" % silencerVersion cross CrossVersion.full),

sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/ScalaReflection.scala

@@ -74,7 +74,7 @@ object ScalaReflection extends ScalaReflection {
   /**
    * Synchronize to prevent concurrent usage of `<:<` operator.
    * This operator is not thread safe in any current version of scala; i.e.
-   * (2.11.12, 2.12.10, 2.13.0-M5).
+   * (2.11.12, 2.12.12, 2.13.0-M5).
    *
    * See https://github.com/scala/bug/issues/10766
    */