Get rid of referenced to WithFixedSym

 - simplify Substituters

Author: odersky

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

@@ -130,10 +130,7 @@ trait Substituters { this: Context =>
         var ts = to
         while (fs.nonEmpty) {
           if (fs.head eq sym)
-            return tp match {
-              case tp: WithFixedSym => NamedType.withFixedSym(tp.prefix, ts.head)
-              case _ => substSym(tp.prefix, from, to, theMap) select ts.head
-            }
+            return substSym(tp.prefix, from, to, theMap) select ts.head
           fs = fs.tail
           ts = ts.tail
         }