Change to PickleFormat

Remove 3rd argument of BIND types. It can be reconstructed
on unpickling.

Author: odersky

src/dotty/tools/dotc/ast/tpd.scala

@@ -409,7 +409,8 @@ object tpd extends Trees.Instance[Type] with TypedTreeInfo {
     override def Select(tree: Tree)(qualifier: Tree, name: Name)(implicit ctx: Context): Select = {
       val tree1 = untpd.cpy.Select(tree)(qualifier, name)
       tree match {
-        case tree: Select if (qualifier.tpe eq tree.qualifier.tpe) => tree1.withTypeUnchecked(tree.tpe)
+        case tree: Select if (qualifier.tpe eq tree.qualifier.tpe) => 
+          tree1.withTypeUnchecked(tree.tpe)
         case _ => tree.tpe match {
           case tpe: NamedType => tree1.withType(tpe.derivedSelect(qualifier.tpe))
           case _ => tree1.withTypeUnchecked(tree.tpe)

src/dotty/tools/dotc/core/pickling/PickleFormat.scala

@@ -135,9 +135,8 @@ Standard-Section: "ASTs" TopLevelStat*
                   ANNOTATED      Length fullAnnotation_Term underlying_Type
                   ANDtype        Length left_Type right_Type
                   ORtype         Length left_Type right_Type
-                  BIND           Length boundName_NameRef bounds_Type selfRef_Type
+                  BIND           Length boundName_NameRef bounds_Type
                                         // for type-variables defined in a type pattern
-                                        // bounds = type bounds, selfRef = reference to type itself.                  
                   BYNAMEtype            underlying_Type
                   POLYtype       Length result_Type NamesTypes      // needed for refinements
                   METHODtype     Length result_Type NamesTypes      // needed for refinements

src/dotty/tools/dotc/core/pickling/TreePickler.scala

@@ -250,8 +250,6 @@ class TreePickler(pickler: TastyPickler) {
         pickleType(tpe.ref)
       case NoType =>
         writeByte(NOTYPE)
-//      case NoPrefix =>    // not sure we need this!
-//        writeByte(NOPREFIX)
     }} catch {
       case ex: AssertionError => 
         println(i"error while pickling type $tpe")

src/dotty/tools/dotc/core/pickling/TreeUnpickler.scala

@@ -201,9 +201,9 @@ class TreeUnpickler(reader: TastyReader, tastyName: TastyName.Table) {
             case ORtype =>
               OrType(readType(), readType())
             case BIND =>
-              symAtAddr(start) = 
-                ctx.newSymbol(ctx.owner, readName().toTypeName, BindDefinedType, readType())
-              readType()
+              val sym = ctx.newSymbol(ctx.owner, readName().toTypeName, BindDefinedType, readType())
+              symAtAddr(start) = sym
+              TypeRef.withFixedSym(NoPrefix, sym.name, sym)
             case POLYtype =>
               val (names, paramReader) = readNamesSkipParams[TypeName]
               val result = PolyType(names)(