Fix dart2dart new_backend

pkg/compiler/lib/src/dart_backend/backend_ast_to_frontend_ast.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.
 
 library dart_tree_printer;
 
 import '../constants/values.dart' as values;
 import '../dart_types.dart' as types;
 import '../dart2jslib.dart' as dart2js;
 import '../elements/elements.dart' as elements;
@@ skipping 958 matching lines @@
           null, // body
           param.type == null ? null : makeType(param.type),
           makeEmptyModifiers(), // TODO: Function parameter modifiers?
           null,  // initializers
           null,  // get/set
           null); // async modifier
       if (param.element != null) {
         setElement(definition, param.element, param);
       }
       if (param.defaultValue != null) {
-        return new tree.SendSet(
+        definition = new tree.SendSet(

[Johnni Winther, 2015/03/05 10:48:01]

This fixes a crash in language/issue13179_test

             null,
             definition,
             new tree.Operator(assignOperator),
             singleton(makeExpression(param.defaultValue)));
-      } else {
-        return new tree.VariableDefinitions(
-            null,
-            makeEmptyModifiers(),
-            singleton(definition));
       }
+      return new tree.VariableDefinitions(
+          null,
+          makeEmptyModifiers(),
+          singleton(definition));
     } else {
       tree.Node definition;
       if (param.defaultValue != null) {
         definition = new tree.SendSet(
             null,
             makeIdentifier(param.name),
             new tree.Operator(assignOperator),
             singleton(makeExpression(param.defaultValue)));
       } else {
         definition = makeIdentifier(param.name);
@@ skipping 334 matching lines @@
             printStringChunk(chunk.previous),
             node);
       } else {
         return node;
       }
     }
     return printStringChunk(output.chunk);
   }
 
 }