fix #603, support mock objects

test/codegen_expected/language/no_such_method_subtype_test.js

Index: test/codegen_expected/language/no_such_method_subtype_test.js
diff --git a/test/codegen_expected/language/no_such_method_subtype_test.js b/test/codegen_expected/language/no_such_method_subtype_test.js
index b4e33db5d2329053a1e02e36713cd2a7bc54fec7..7d2c5cf41a15788e6e170b92ca70bc1c5cb2528f 100644
--- a/test/codegen_expected/language/no_such_method_subtype_test.js
+++ b/test/codegen_expected/language/no_such_method_subtype_test.js
@@ -23,6 +23,9 @@ dart_library.library('language/no_such_method_subtype_test', null, /* Imports */
     noSuchMethod(im) {
       return 84;
     }
+    foo() {
+      return this.noSuchMethod(new dart.InvocationImpl('foo', [], {isMethod: true}));
+    }
   };
   no_such_method_subtype_test.B[dart.implements] = () => [no_such_method_subtype_test.A];
   no_such_method_subtype_test.main = function() {