Attach type info to extension method and object method tear-offs

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 core = dart_library.import('dart/core');
 var collection = dart_library.import('dart/collection');
 var dart = dart_library.import('dart_runtime/dart');
 var dartx = dart.dartx;
 
@@ skipping 657 matching lines @@
               dart.functionType(dart.void, [core.int]));
     checkType(dart.bind(listB, dartx.add),
               dart.functionType(dart.void, [core.String]), false, true);
 
     // Tear off of a static method
     checkType(c.ListBase.listToString,
               dart.functionType(core.String, [core.List]));
     checkType(c.ListBase.listToString,
               dart.functionType(core.String, [core.String]), false, true);
 
+    // Tear-off of extension methods on primitives
+    checkType(dart.bind(3.0, dartx.floor),
+              dart.functionType(core.int, []));
+    checkType(dart.bind(3.0, dartx.floor),
+              dart.functionType(core.String, []), false, true);
+    checkType(dart.bind("", dartx.endsWith),
+              dart.functionType(core.bool, [core.String]));
+    checkType(dart.bind("", dartx.endsWith),
+              dart.functionType(core.bool, [core.int]), false, true);
+
     // Tear off a mixin method
     class Base {
       m(x) {return x;}
     };
     dart.setSignature(Base, {
       methods: () => ({
         m: [core.int, [core.int]],
       })
     });
 
@@ skipping 78 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));
   });
 });