Allow null args to dynamic invocations

test/browser/runtime_tests.js

 // Copyright (c) 2015, 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.
 
 var assert = chai.assert;
 
 suite('generic', () => {
   "use strict";
 
   let generic = dart.generic;
@@ skipping 438 matching lines @@
       }),
       statics: () => ({
         s: [core.String, [core.String]]
       }),
       names: ['s']
     })
     let o = new Tester();
 
     // Method send
     assert.equal(dart.dsend(o, 'm', 3, 4), 3);
+    assert.equal(dart.dsend(o, 'm', null, 4), null);
     assert.throws(() => dart.dsend(o, 'm', 3));
     assert.throws(() => dart.dsend(o, 'm', "hello", "world"));
     assert.throws(() => dart.dsend(o, 'q', 3));
 
     // Method send through a field
     assert.equal(dart.dsend(o, 'f', 3), 3);
+    assert.equal(dart.dsend(o, 'f', null), null);
     assert.throws(() => dart.dsend(o, 'f', "hello"));
     assert.throws(() => dart.dsend(o, 'f', 3, 4));
 
     // Static method call
     assert.equal(dart.dcall(Tester.s, "hello"), "hello");
+    assert.equal(dart.dcall(Tester.s, null), null);
     assert.throws(() => dart.dcall(Tester.s, "hello", "world"));
     assert.throws(() => dart.dcall(Tester.s, 0, 1));
 
     // Calling an object with a call method
     assert.equal(dart.dcall(o, 3), 3);
+    assert.equal(dart.dcall(o, null), null);
     assert.throws(() => dart.dcall(o, "hello"));
     assert.throws(() => dart.dcall(o, 3, 4));
 
     // Calling through a field containing an object with a call method
     assert.equal(dart.dsend(o, 'me', 3), 3);
+    assert.equal(dart.dsend(o, 'me', null), null);
     assert.throws(() => dart.dsend(o, 'me', "hello"));
     assert.throws(() => dart.dsend(o, 'me', 3, 4));
   });
 
   test('Types on top level functions', () => {
     // Test some generated code
     // Test the lazy path
     checkType(core.identityHashCode,
               dart.functionType(core.int, [core.Object]));
     // Test the normal path
@@ skipping 184 matching lines @@
 
 suite('primitives', function() {
   'use strict';
 
   test('fixed length list', () => {
     let list = new core.List(10);
     list[0] = 42;
     assert.throws(() => list.add(42));
   });
 });