dart2js cps: Refactor CallExpressions into Primitives.

tests/compiler/dart2js/js_backend_cps_ir_closures_test.dart

 // Copyright (c) 2014, 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.
 
 // Tests of closures.
 
 library closures_test;
 
 import 'js_backend_cps_ir.dart';
 
@@ skipping 229 matching lines @@
     return (x) => x;
   }
 }
 main(x) {
   var notTearOff = new Foo().getter;
   print(notTearOff(123));
 }
 """,
 r"""
 function(x) {
-  P.print(V.Foo$().getter$1(123));
+  P.print(V.Foo$().get$getter().call$1(123));
 }"""),
 ];
 
 void main() {
   runTests(tests);
 }