Support constructor declarations in analyzer2dart.

pkg/compiler/lib/src/cps_ir/shrinking_reductions.dart

 // Copyright (c) 2014, 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.
 
 part of dart2js.cps_ir.optimizers;
 
 /**
  * [ShrinkingReducer] applies shrinking reductions to CPS terms as described
  * in 'Compiling with Continuations, Continued' by Andrew Kennedy.
  */
@@ skipping 462 matching lines @@
   }
 
   processRunnableBody(RunnableBody node) {
     node.returnContinuation.parent = node;
     node.body.parent = node;
   }
 
   processConstructorDefinition(ConstructorDefinition node) {
     node.body.parent = node;
     int index = 0;
-    node.parameters.forEach((Parameter parameter) {
+    node.parameters.forEach((Definition parameter) {
       parameter.parent = node;
-      parameter.parent_index = index++;
+      if (parameter is Parameter) parameter.parent_index = index++;
     });
     node.initializers.forEach((Initializer i) => i.parent = node);
   }
 
   // Expressions.
 
   processFieldInitializer(FieldInitializer node) {
     node.body.body.parent = node;
   }
 
@@ skipping 167 matching lines @@
   }
 
   String toString() => "$kind: $node";
 }
 
 /// A dummy class used solely to mark nodes as deleted once they are removed
 /// from a term.
 class _DeletedNode extends Node {
   accept(_) => null;
 }