Fix VariableDefinitions.endToken for formal parameters.

tests/compiler/dart2js/resolver_test.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.
 
 import 'dart:collection';
 import 'dart:uri';
 
 import "../../../sdk/lib/_internal/compiler/implementation/resolution/resolution.dart";
 import "../../../sdk/lib/_internal/compiler/implementation/elements/elements.dart";
 import "../../../sdk/lib/_internal/compiler/implementation/tree/tree.dart";
@@ skipping 17 matching lines @@
   for (final variable in variables) {
     String name = variable[0];
     bool init = variable[1];
     if (init) {
       locals.add(buildInitialization(name));
     } else {
       locals.add(buildIdentifier(name));
     }
   }
   var definitions = new NodeList(null, new Link.fromList(locals), null, null);
-  return new VariableDefinitions(null, Modifiers.EMPTY, definitions, null);
+  return new VariableDefinitions(null, Modifiers.EMPTY, definitions);
 }
 
 testLocals(List variables) {
   MockCompiler compiler = new MockCompiler();
   ResolverVisitor visitor = compiler.resolverVisitor();
   Element element = visitor.visit(createLocals(variables));
   // A VariableDefinitions does not have an element.
   Expect.equals(null, element);
   Expect.equals(variables.length, map(visitor).length);
 
@@ skipping 793 matching lines @@
         var d = new D();
         --d;
       }""";
   final compiler = compileScript(script);
 
   checkMemberResolved(compiler, 'A', operatorName('+', false));
   checkMemberResolved(compiler, 'B', operatorName('+', false));
   checkMemberResolved(compiler, 'C', operatorName('-', false));
   checkMemberResolved(compiler, 'D', operatorName('-', false));
 }