Issue 3084. Generate warning, not error, for 'Unknown.unknown'

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.
@@ skipping 51 matching lines @@
 gc_test: Skip  # Takes too long.
 
 [ $compiler == dartc ]
 application_negative_test: Fail # Runtime only test, rewrite as multitest
 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
 cascade_test: Pass,Fail # Issue 3729  Some cases pass, but for the wrong reason
 char_escape_test: Pass # Issue 1654
+class_literal_test/04 : Skip # language change 1031
+class_literal_test/09 : Skip # language change 1031
+class_literal_test/16 : Skip # language change 1031
 closure_call_wrong_argument_count_negative_test: Fail # Runtime only test, rewrite as multitest
 constructor3_negative_test: Fail # Runtime only test, rewrite as multitest
 constructor_call_wrong_argument_count_negative_test: Fail # Runtime only test, rewrite as multitest
 disable_privacy_test: Skip  # Issue 1882: Needs --disable_privacy support.
 duplicate_implements_test: Skip # Issue 976
 factory5_test/00: Fail # issue 3079
 field_method4_negative_test: Fail  # Runtime only test, rewrite as multitest
 final_syntax_test/*: Skip  # can't handle base case
 getter_no_setter_test/01: Fail # Fails to detect compile-time error.
 instance_call_wrong_argument_count_negative_test: Fail # Runtime only test, rewrite as multitest
 is_not_class2_negative_test: Fail #  Runtime only test, rewrite as multitest
 library2_negative_test: Fail # still a valid test? Issue 3649
 library4_negative_test: Fail # still a valid test? Issue 3530
 library6_negative_test: Fail # still a valid test? Issue 3650
 list_literal4_test: Fail       # Issue 1343
 map_literal4_test: Fail        # Issue 1343
 named_parameters_negative_test: Fail # Runtime only test, rewrite as multitest
 named_parameters_with_object_property_names_test: Fail # Issue 2137
 no_such_method_negative_test: Fail # Runtime only test, rewrite as multiteste
 override_field_test/03: Fail # still a valid test? Issue 3894
 override_field_test/04: Fail # still a valid test? Issue 3656
+prefix1_negative_test : Skip # language change 1031
+prefix5_negative_test : Skip # language change 1031
 private_member3_negative_test: Fail # Runtime only test?  rewrite as multitest
 pseudo_kw_illegal_test/08: Fail # Issue 356
 pseudo_kw_illegal_test/10: Fail # Issue 356
 pseudo_kw_illegal_test/14: Fail # Issue 356
 setter_no_getter_call_test/01: Fail # Issue 4383
 static_call_wrong_argument_count_negative_test: Fail # Runtime only test, rewrite as multitest
 syntax_test: Skip              # Bug 2107  Static type warnings in none case
 throw7_negative_test: Fail     # Issue 3654
 try_catch_test: Fail # Uses new catch syntax.
 # try_catch_syntax_test/08: Fail # Issue 3795
@@ skipping 202 matching lines @@
 static_top_level_test/05: Fail
 string_interpolation7_test: Fail
 switch_label_test: Fail
 syntax_test/none: Fail
 typed_message_test: Fail
 type_variable_bounds2_test/02: Fail
 type_variable_bounds2_test/06: Fail
 type_variable_bounds_test/02: Fail
 type_variable_bounds_test/04: Fail
 type_variable_bounds_test/05: Fail