Fix test status

pkg/dev_compiler/test/not_yet_strong_tests.dart

Index: pkg/dev_compiler/test/not_yet_strong_tests.dart
diff --git a/pkg/dev_compiler/test/not_yet_strong_tests.dart b/pkg/dev_compiler/test/not_yet_strong_tests.dart
index 0d67109d067cb2e1bf96a7e4fc11140448de1a3b..335be0b306ac68e5393804ffd7535b8ad88cefe3 100644
--- a/pkg/dev_compiler/test/not_yet_strong_tests.dart
+++ b/pkg/dev_compiler/test/not_yet_strong_tests.dart
@@ -784,6 +784,7 @@ final notYetStrongTests = new HashSet<String>.from([
   'language/generic_field_mixin6_test_01_multi',
   'language/generic_field_mixin6_test_none_multi',
   'language/generic_list_checked_test',
+  'language/generic_tearoff_test',
   'language/generic_test',
   'language/generics_test',
   'language/get_set_syntax_test_00_multi',
@@ -1201,7 +1202,6 @@ final notYetStrongTests = new HashSet<String>.from([
   'language/mixin_lib_extends_field_test',
   'language/mixin_lib_extends_method_test',
   'language/mixin_method_test',
-  'language/mixin_mixin_bound_test', // issue 28450
   'language/mixin_super_bound2_test_01_multi',
   'language/mixin_super_bound2_test_none_multi',
   'language/mixin_super_bound_test',
@@ -2125,7 +2125,6 @@ final notYetStrongTests = new HashSet<String>.from([
   'lib/mirrors/generic_class_declaration_test',
   'lib/mirrors/generic_f_bounded_mixin_application_test',
   'lib/mirrors/generic_interface_test_01_multi',
-  'lib/mirrors/generics_dynamic_test', // issue 28450
   'lib/mirrors/generics_test_01_multi',
   'lib/mirrors/get_symbol_name_no_such_method_test',
   'lib/mirrors/immutable_collections_test',