Implement call operator.

tests/compiler/dart2js/closure_codegen_test.dart

 // Copyright (c) 2012, 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.
 // Test that parameters keep their names in the output.
 
 #import("compiler_helper.dart");
 #import("parser_helper.dart");
 
 final String TEST_INVOCATION0 = @"""
 main() {
@@ skipping 23 matching lines @@
     var f = function g() { return 499;  };
     return 499 + x + f();
   }
 }
 
 main() { new A().foo(); }
 """;
 
 closureInvocation() {
   String generated = compile(TEST_INVOCATION0);
-  Expect.isTrue(generated.contains(".\$call\$0()"));
+  Expect.isTrue(generated.contains(@".call$0()"));
   generated = compile(TEST_INVOCATION1);
-  Expect.isTrue(generated.contains(@".$call$1(1)"));
+  Expect.isTrue(generated.contains(@".call$1(1)"));
   generated = compile(TEST_INVOCATION2);
-  Expect.isTrue(generated.contains(@".$call$2(1, 2)"));
+  Expect.isTrue(generated.contains(@".call$2(1, 2)"));
 }
 
 // Make sure that the bailout version does not introduce a second version of
 // the closure.
 closureBailout() {
   String generated = compileAll(TEST_BAILOUT);
-  RegExp regexp = const RegExp(@'\$call\$0: function');
+  RegExp regexp = const RegExp(@'call\$0: function');
   Iterator<Match> matches = regexp.allMatches(generated).iterator();
   checkNumberOfMatches(matches, 1);
 }
 
 main() {
   closureInvocation();
   closureBailout();
 }