Drop unused name tags

Drop unused AvoidClashName name kind and name tags
AVIDCLASH and DIRECT

Author: odersky

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

@@ -128,7 +128,7 @@ object NameOps {
     /** If flags is a ModuleClass but not a Package, add module class suffix */
     def adjustIfModuleClass(flags: FlagSet): N = likeSpacedN {
       if (flags.is(ModuleClass, butNot = Package)) name.asTypeName.moduleClassName
-      else name.toTermName.exclude(AvoidClashName)
+      else name.toTermName
     }
 
     /** The expanded name.

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

@@ -17,13 +17,6 @@ object NameTags extends TastyFormat.NameTags {
 
   final val INITIALIZER = 26    // A mixin initializer method
 
-  final val AVOIDCLASH = 27     // Adds a suffix to avoid a name clash;
-                                // Used in FirstTransform for synthesized companion objects of classes
-                                // if they would clash with another value.
-
-  final val DIRECT = 28         // Used by ShortCutImplicits for the name of methods that
-                                // implement implicit function result types directly.
-
   final val FIELD = 29          // Used by Memoize to tag the name of a class member field.
 
   final val EXTMETH = 30        // Used by ExtensionMethods for the name of an extension method
@@ -51,8 +44,6 @@ object NameTags extends TastyFormat.NameTags {
     case INLINEACCESSOR => "INLINEACCESSOR"
     case PROTECTEDACCESSOR => "PROTECTEDACCESSOR"
     case INITIALIZER => "INITIALIZER"
-    case AVOIDCLASH => "AVOIDCLASH"
-    case DIRECT => "DIRECT"
     case FIELD => "FIELD"
     case EXTMETH => "EXTMETH"
     case IMPLMETH => "IMPLMETH"

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

@@ -282,7 +282,7 @@ object SymDenotations {
      */
     def effectiveName(implicit ctx: Context): Name =
       if (this.is(ModuleClass)) name.stripModuleClassSuffix
-      else name.exclude(AvoidClashName)
+      else name
 
     /** The privateWithin boundary, NoSymbol if no boundary is given.
      */

compiler/src/dotty/tools/dotc/typer/Checking.scala

@@ -851,7 +851,7 @@ trait Checking {
     typr.println(i"check no double declarations $cls")
 
     def checkDecl(decl: Symbol): Unit = {
-      for (other <- seen(decl.name) if (!decl.isAbsent() && !other.isAbsent())) {
+      for (other <- seen(decl.name) if !decl.isAbsent() && !other.isAbsent()) {
         typr.println(i"conflict? $decl $other")
         def javaFieldMethodPair =
           decl.is(JavaDefined) && other.is(JavaDefined) &&

library/src/scala/annotation/internal/Child.scala

@@ -1,6 +1,5 @@
-package scala.annotation.internal
-
-import scala.annotation.Annotation
+package scala.annotation
+package internal
 
 /** An annotation to indicate a child class or object of the annotated class.
  *  E.g. if we have