Improvements for checked mode: check when intializing fields, and when assigning to fields.

pkg/pkg.status

 # 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.
 
 # Run this test manually to verify that the fixnum library produces
 # the same results as native ints on a set of directed and random inputs.
 # Skip it when runnimng automated tests because it times out.  This
 # test only makes sense on runtimes that support 64-bit integer
 # arithmetic natively, i.e., the VM.
 fixnum/test/int_64_vm_test: Skip
 
 [$compiler == dart2dart]
 *: Skip
 
 [ $runtime == opera ]
 *: Skip
 
 [ $compiler == dartc ]
 unittest/test/mock_regexp_negative_test: fail
 unittest/test/mock_stepwise_negative_test: fail
 
 [ $compiler == dart2js || $compiler == dartc ]
 unittest/test/instance_test: Skip
 
 [ $compiler == dart2js && $checked ]
-fixnum/test/int_32_test: Fail # Issue 3720.
-fixnum/test/int_64_test: Fail # Issue 3720.
+# The following tests fail on int checks.
+# Issue 3720
+fixnum/test/int_32_test: Fail
+fixnum/test/int_64_test: Fail
+args/test/args_test: Fail
+intl/test/bidi_format_test: Fail
+intl/test/bidi_utils_test: Fail
+intl/test/date_time_format_test: Fail
+intl/test/intl_message_test: Fail
+intl/test/intl_test: Fail
+intl/test/number_format_test: Fail
+logging/test/logging_test: Fail
+unittest/test/matchers_test: Fail
+unittest/test/mock_test: Fail
+unittest/test/unittest_test: Fail