Implement tear-off closure operator #

tests/language/tearoff_basic_lib.dart

 // 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.
 
-library shared;
+library tearoff_basic_lib;
 
-class CShared {
-  toString() => "shared";
-}
+cfunc() => "cfunc";
 
-class C1 {
-  toString() => "C1";
-}
+set cset(a) { cvar = a; }
 
-class C2 {
-  toString() => "C2";
-}
+get cget => "cget";
+
+var cvar = 1+2+3;
+
+final cfinvar = "set in stone";
+
+class ZZ { }