implement generic method runtime behavior, fixes #301

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;
 var dart_sdk = dart_library.import('dart_sdk');
 var core = dart_sdk.core;
 var collection = dart_sdk.collection;
 var dart = dart_sdk.dart;
 var dartx = dart.dartx;
@@ skipping 590 matching lines @@
 
     // Set the type eagerly
     function ii2i(x, y) {return x};
     dart.fn(ii2i, core.int, [core.int, core.int]);
     checkType(ii2i, dart.functionType(core.int,
                                       [core.int, core.int]));
 
     // Set the type lazily
     function ss2s(x, y) {return x};
     var coreString;
-    dart.fn(ss2s, () => dart.functionType(coreString,
-                                          [coreString, coreString]));
+    dart.lazyFn(ss2s, () => [coreString, [coreString, coreString]]);
     coreString = core.String;
     checkType(ss2s, dart.functionType(core.String,
                                       [core.String, core.String]));
 
     // Optional types
     function ii_2i(x, y) {return x};
     dart.fn(ii_2i, core.int, [core.int], [core.int]);
     checkType(ii_2i, dart.functionType(core.int, [core.int],
                                        [core.int]));
     checkType(ii_2i, dart.functionType(core.int, [core.int,
@@ skipping 162 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));
   });
 });