Fix testNonCyclic test

Author: nicolasstucki

compiler/src/dotty/tools/dotc/CompilationUnit.scala

@@ -1,9 +1,9 @@
 package dotty.tools
 package dotc
 
+import dotty.tools.dotc.core.Types.Type // FIXME Why is this import needed in posTwice testNonCyclic?
 import util.SourceFile
-import ast.{tpd, untpd}
-import dotty.tools.dotc.ast.tpd.{ Tree, TreeTraverser }
+import dotty.tools.dotc.ast.{ tpd, untpd }
 import dotty.tools.dotc.core.Contexts.Context
 import dotty.tools.dotc.core.SymDenotations.ClassDenotation
 import dotty.tools.dotc.core.Symbols._
@@ -25,7 +25,7 @@ class CompilationUnit(val source: SourceFile) {
 object CompilationUnit {
 
   /** Make a compilation unit for top class `clsd` with the contends of the `unpickled` */
-  def mkCompilationUnit(clsd: ClassDenotation, unpickled: Tree, forceTrees: Boolean)(implicit ctx: Context): CompilationUnit = {
+  def mkCompilationUnit(clsd: ClassDenotation, unpickled: tpd.Tree, forceTrees: Boolean)(implicit ctx: Context): CompilationUnit = {
     val file = Option(clsd.symbol.sourceFile).getOrElse(clsd.symbol.associatedFile)
     val unit1 = new CompilationUnit(new SourceFile(file, Seq()))
     unit1.tpdTree = unpickled
@@ -35,7 +35,7 @@ object CompilationUnit {
   }
 
   /** Force the tree to be loaded */
-  private object force extends TreeTraverser {
-    def traverse(tree: Tree)(implicit ctx: Context): Unit = traverseChildren(tree)
+  private object force extends tpd.TreeTraverser {
+    def traverse(tree: tpd.Tree)(implicit ctx: Context): Unit = traverseChildren(tree)
   }
 }