dart2js cps: Replace getter/setter calls with direct field access.

tests/language/dead_field_access_test.dart

Index: tests/language/dead_field_access_test.dart
diff --git a/tests/language/regress_21998_1_test.dart b/tests/language/dead_field_access_test.dart
similarity index 61%
copy from tests/language/regress_21998_1_test.dart
copy to tests/language/dead_field_access_test.dart
index 3237f3396629f6fd11270e1adc290bec78713958..e3fc11b6c5f33af074b45ea57a53194aadb20daa 100644
--- a/tests/language/regress_21998_1_test.dart
+++ b/tests/language/dead_field_access_test.dart
@@ -2,17 +2,19 @@
 // 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.
 
-import 'dart:math' as Math;
 import 'package:expect/expect.dart';
 
-main() {
-  Expect.equals(4, new C().m());
+class Foo {
+  var field = 10;
 }
 
-class C {
-  max(a) => a;
+@NoInline()
+getField(x) {
+  x.field;
+  return 34;
+}
 
-  m() {
-    return max(Math.max(2, 4));
-  }
-}
+main() {
+  Expect.equals(34, getField(new Foo()));
+  Expect.throws(() => getField(null));
+}