Update docs, plugins, and build to use new setting

Author: odersky

docs/docs/reference/dropped-features/auto-apply.md

@@ -785,7 +785,7 @@ object Build {
   lazy val tastyCoreSettings = Seq(
     scalacOptions ~= { old =>
       val (language, other) = old.partition(_.startsWith("-language:"))
-      other :+ (language.headOption.map(_ + ",Scala2Compat").getOrElse("-language:Scala2Compat"))
+      other :+ (language.headOption.map(_ + ",Scala2Compat").getOrElse("-source:3.0-migration"))
     }
   )
 

docs/docs/reference/dropped-features/procedure-syntax.md

@@ -7,6 +7,6 @@ object DottyInjectedPlugin extends AutoPlugin {
 
   override val projectSettings = Seq(
     scalaVersion := sys.props("plugin.scalaVersion"),
-    scalacOptions += "-language:Scala2Compat"
+    scalacOptions += "-source:3.0-migration"
   )
 }

docs/docs/reference/features-classification.md

@@ -7,6 +7,6 @@ object DottyInjectedPlugin extends AutoPlugin {
 
   override val projectSettings = Seq(
     scalaVersion := sys.props("plugin.scalaVersion"),
-    scalacOptions += "-language:Scala2Compat"
+    scalacOptions += "-source:3.0-migration"
   )
 }

docs/docs/reference/overview.md

@@ -7,6 +7,6 @@ object DottyInjectedPlugin extends AutoPlugin {
 
   override val projectSettings = Seq(
     scalaVersion := sys.props("plugin.scalaVersion"),
-    scalacOptions += "-language:Scala2Compat"
+    scalacOptions += "-source:3.0-migration"
   )
 }

project/Build.scala

@@ -7,6 +7,6 @@ object DottyInjectedPlugin extends AutoPlugin {
 
   override val projectSettings = Seq(
     scalaVersion := sys.props("plugin.scalaVersion"),
-    scalacOptions += "-language:Scala2Compat"
+    scalacOptions += "-source:3.0-migration"
   )
 }

sbt-dotty/sbt-test/compilerReporter/simple/project/DottyInjectedPlugin.scala

@@ -7,6 +7,6 @@ object DottyInjectedPlugin extends AutoPlugin {
 
   override val projectSettings = Seq(
     scalaVersion := sys.props("plugin.scalaVersion"),
-    scalacOptions += "-language:Scala2Compat"
+    scalacOptions += "-source:3.0-migration"
   )
 }