Remove methods that detected wrong classes loaded

Now we load them from their .tasty which ensures that the class was generated by Scala 3 (not Scala 2 nor Java).

Author: nicolasstucki

compiler/src/dotty/tools/dotc/fromtasty/JavaCompilationUnit.scala

@@ -44,9 +44,8 @@ class ReadTasty extends Phase {
                 Some(unit)
               }
             case tree: Tree[?] =>
+              // TODO handle correctly this case correctly to get the tree or avoid it completely.
               cls.denot.infoOrCompleter match {
-                case _: NoLoader => Some(Scala2CompilationUnit(cls.fullName.toString))
-                case _ if cls.flags.is(Flags.JavaDefined) => Some(JavaCompilationUnit(cls.fullName.toString))
                 case _ => Some(AlreadyLoadedCompilationUnit(cls.denot.fullName.toString))
               }
             case _ =>

compiler/src/dotty/tools/dotc/fromtasty/ReadTasty.scala

@@ -2585,15 +2585,6 @@ class QuoteContextImpl private (ctx: Context) extends QuoteContext, scala.intern
 
     object Source extends SourceModule:
       def path: java.nio.file.Path = ctx.compilationUnit.source.file.jpath
-      def isJavaCompilationUnit: Boolean = ctx.compilationUnit.isInstanceOf[dotc.fromtasty.JavaCompilationUnit]
-      def isScala2CompilationUnit: Boolean = ctx.compilationUnit.isInstanceOf[dotc.fromtasty.Scala2CompilationUnit]
-      def isAlreadyLoadedCompilationUnit: Boolean = ctx.compilationUnit.isInstanceOf[dotc.fromtasty.AlreadyLoadedCompilationUnit]
-      def compilationUnitClassname: String =
-        ctx.compilationUnit match
-          case cu: dotc.fromtasty.JavaCompilationUnit => cu.className
-          case cu: dotc.fromtasty.Scala2CompilationUnit => cu.className
-          case cu: dotc.fromtasty.AlreadyLoadedCompilationUnit => cu.className
-          case cu => ""
     end Source
 
     object Reporting extends ReportingModule:

compiler/src/dotty/tools/dotc/fromtasty/Scala2CompilationUnit.scala

@@ -3265,17 +3265,6 @@ trait Reflection { reflection =>
     /** Returns the source file being compiled. The path is relative to the current working directory. */
     def path: java.nio.file.Path
 
-    /** Returns true if we've tried to reflect on a Java class. */
-    def isJavaCompilationUnit: Boolean
-
-    /** Returns true if we've tried to reflect on a Scala2 (non-Tasty) class. */
-    def isScala2CompilationUnit: Boolean
-
-    /** Returns true if we've tried to reflect on a class that's already loaded (e.g. Option). */
-    def isAlreadyLoadedCompilationUnit: Boolean
-
-    /** Class name of the current CompilationUnit */
-    def compilationUnitClassname: String
   }
 
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