Remove unused designator methods

Author: odersky

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

@@ -18,14 +18,11 @@ object Designators {
     type ThisName <: Name
 
     /** Classifiers and casts, to be overridden in implemetations */
-    def isName: Boolean = false
-    def isSymbol: Boolean = false
-
     def isTerm(implicit ctx: Context) = false
     def isType(implicit ctx: Context) = false
 
-    def asTerm(implicit ctx: Context): TermDesignator = unsupported("asTerm")
-    def asType(implicit ctx: Context): TypeDesignator = unsupported("asType")
+    def asTerm(implicit ctx: Context): TermDesignator
+    def asType(implicit ctx: Context): TypeDesignator
 
     def withNameSpace(space: NameSpace)(implicit ctx: Context): Designator { type ThisName = self.ThisName } =
       if (space == noNameSpace) this

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

@@ -155,7 +155,6 @@ object Names {
     def endsWith(str: String): Boolean = lastPart.endsWith(str)
 
     /** Designator overrides */
-    override def isName = true
     override def isTerm(implicit ctx: Context) = isTermName
     override def isType(implicit ctx: Context) = isTypeName
     override def asTerm(implicit ctx: Context) = asTermName

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

@@ -444,7 +444,6 @@ object Symbols {
       lastDenot.validFor.runId == ctx.runId || ctx.stillValid(lastDenot)
 
     /** Designator overrides */
-    final override def isSymbol = true
     final override def isTerm(implicit ctx: Context): Boolean =
       (if (defRunId == ctx.runId) lastDenot else denot).isTerm
     final override def isType(implicit ctx: Context): Boolean =