Change -scala-release flag into proper VersionSetting

Author: Kordyjan

compiler/src/dotty/tools/dotc/config/ScalaSettings.scala

@@ -101,7 +101,7 @@ trait CommonScalaSettings:
   val silentWarnings: Setting[Boolean] = BooleanSetting("-nowarn", "Silence all warnings.", aliases = List("--no-warnings"))
 
   val release: Setting[String] = ChoiceSetting("-release", "release", "Compile code with classes specific to the given version of the Java platform available on the classpath and emit bytecode for this version.", ScalaSettings.supportedReleaseVersions, "", aliases = List("--release"))
-  val scalaRelease: Setting[String] = ChoiceSetting("-scala-release", "release", "Emit TASTy files that can be consumed by specified version of the compiler.", List("3.0", "3.1"), "3.1", aliases = List("--scala-release"))
+  val scalaRelease: Setting[ScalaVersion] = VersionSetting("-scala-release", "Emit TASTy files that can be consumed by specified version of the compiler.")
   val deprecation: Setting[Boolean] = BooleanSetting("-deprecation", "Emit warning and location for usages of deprecated APIs.", aliases = List("--deprecation"))
   val feature: Setting[Boolean] = BooleanSetting("-feature", "Emit warning and location for usages of features that should be imported explicitly.", aliases = List("--feature"))
   val explain: Setting[Boolean] = BooleanSetting("-explain", "Explain errors in more detail.", aliases = List("--explain"))

compiler/src/dotty/tools/dotc/core/Contexts.scala

@@ -39,6 +39,7 @@ import plugins._
 import java.util.concurrent.atomic.AtomicInteger
 import java.nio.file.InvalidPathException
 import dotty.tools.tasty.TastyFormat
+import dotty.tools.dotc.config.{ NoScalaVersion, SpecificScalaVersion, AnyScalaVersion }
 
 object Contexts {
 
@@ -485,10 +486,11 @@ object Contexts {
 
     def tastyVersion: (Int, Int, Int) =
       base.settings.scalaRelease.value match
-        case "" =>
+        case NoScalaVersion =>
           import TastyFormat.*
           (MajorVersion, MinorVersion, ExperimentalVersion)
-        case s"$maj.$min" => (maj.toInt + 25, min.toInt, 0)
+        case SpecificScalaVersion(maj, min, _, _) => (maj.toInt + 25, min.toInt, 0)
+        case AnyScalaVersion => (28, 0, 0) // 3.0
 
     /** Is the debug option set? */
     def debug: Boolean = base.settings.Ydebug.value

compiler/test/dotty/tools/vulpix/ParallelTesting.scala

@@ -215,7 +215,7 @@ trait ParallelTesting extends RunnerOrchestration { self =>
 
         case testSource @ SeparateCompilationSource(_, dir, flags, outDir) =>
           testSource.compilationGroups.map { (group, files) =>
-            val flags1 = if group.target.isEmpty then flags else flags.and("-scala-release", group.target)
+            val flags1 = if group.target.isEmpty then flags else flags.and(s"-scala-release:${group.target}")
             if group.compiler.isEmpty then
               compile(files, flags1, suppressErrors, outDir)
             else