Implement unresolved super-send (but ignoring arguments).

dart/frog/leg/elements/elements.dart

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #library('elements');
 
 #import('../tree/tree.dart');
 #import('../scanner/scannerlib.dart');
 #import('../leg.dart');  // TODO(karlklose): we only need type.
 #import('../util/util.dart');
@@ skipping 153 matching lines @@
   }
 
   LibraryElement getLibrary() {
     Element element = this;
     while (element.kind !== ElementKind.LIBRARY) {
       element = element.enclosingElement;
     }
     return element;
   }
 
+  ClassElement getEnclosingClass() {
+    for (Element e = this; e !== null; e = e.enclosingElement) {
+      if (e.kind === ElementKind.CLASS) return e;
+    }
+    return null;
+  }
+
   toString() => '$kind(${name.slowToString()})';
 
   bool _isNative = false;
   void setNative() => _isNative = true;
   bool isNative() => _isNative;
 }
 
 class ContainerElement extends Element {
   ContainerElement(name, kind, enclosingElement) :
     super(name, kind, enclosingElement);
@@ skipping 748 matching lines @@
   final Node node;
   Type bound;
   Type type;
   TypeVariableElement(name, Element enclosing, this.node, this.type,
                       [this.bound])
     : super(name, ElementKind.TYPE_VARIABLE, enclosing);
   Type computeType(compiler) => type;
   Node parseNode(compiler) => node;
   toString() => "${enclosingElement.toString()}.${name.slowToString()}";
 }