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

tests/language/language.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.
 
 # This directory contains tests that are intended to show the
 # current state of the language.
 
 # In order to maintain maximum test coverage for all builds,
 # please use the following procedure to mark a test
 # failed on architectures other than the one you are working on.
 #
 # 1) Copy the old version of the test to
 #    tests/language/src/test_name_[dartc|vm]_test.dart.
 #    to maintain coverage.
 # 2) File a bug on each architecture for the failure due to the language change.
 # 3) Update the language/src directory with the updated test.
 
 [ $compiler == none ]
 call_constructor_on_unresolvable_class_test/01: Fail # Issue 3801
 call_constructor_on_unresolvable_class_test/02: Fail # Issue 3801
 call_constructor_on_unresolvable_class_test/03: Fail # Issue 3801
 call_constructor_on_unresolvable_class_test/07: Fail # Issue 3801
 call_nonexistent_constructor_test: Fail # Issue 3801
 gc_test: Fail # Issue 1487
 field_override_test/none: Fail  # Issue 742: field shadowing now allowed
 field_override_test/01: Fail    # Issue 742: field shadowing now allowed
-field_override_test/02: Fail    # Issue 742: field shadowing now allowed
 super_field_access_test: Fail    # Issue 742: field shadowing now allowed
 pseudo_kw_illegal_test/03: Fail  # Issue 356
 pseudo_kw_illegal_test/08: Fail  # Issue 356
 pseudo_kw_illegal_test/10: Fail  # Issue 356
 pseudo_kw_illegal_test/14: Fail  # Issue 356
 final_field_initialization_order_test: Fail # Issue 4839
 
 # These bugs refer currently ongoing language discussions.
 constructor5_test: Fail          # (Discussion ongoing)
 constructor6_test: Fail          # (Discussion ongoing)
@@ skipping 31 matching lines @@
 lazy_static4_test: Fail # Issue 3558
 
 
 # DartC specific tests that should not be run by the VM
 *dartc_test: Skip
 *dartc_negative_test: Skip
 
 [ $compiler == none && $mode == debug ]
 gc_test: Skip  # Takes too long.
 
+[ $compiler == none && $unchecked ]
+field_override_test/02: Fail    # Issue 742: field shadowing now allowed
+
 [ $compiler == dartc ]
 
 get_set_syntax_test/none: Fail # does not accept getter/setter with no method body
 application_negative_test: Fail # Runtime only test, rewrite as multitest
 interface_negative_test: Fail # instantiation of abstract class
 argument_definition_test/*: Skip # Not implemented.
 assert_keyword_negative_test: Fail # Runtime only test, rewrite as multitest
 assign_instance_method_negative_test: Fail  # Runtime only test, rewrite as multitest
 body_less_constructor_wrong_arg_negative_test: Fail  # Runtime only test, rewrite as multitest
 call_operator_test: Pass # Issue 1355
@@ skipping 234 matching lines @@
 disable_privacy_test: Fail, Ok
 # This test hard codes name of file being run and precise position.
 generic_test: Fail, Ok
 # Minified mode failures.
 # TODO(antonm): proper support in test framework.
 overridden_no_such_method_test: Pass, Fail, OK # Hard codes the name of invoked method ("foo").
 many_overridden_no_such_method_test: Pass, Fail, OK # Hard codes the name of invoked method ("foo").
 no_such_method_test: Pass, Fail, OK # Hard codes the name of invoked method ("foo").
 
 named_parameters_aggregated_test/05: Fail # Compile-time error reported instead of static type warning.