Add negation to single-identifier tests in status files.

tests/language/language_dart2js.status

Index: tests/language/language_dart2js.status
diff --git a/tests/language/language_dart2js.status b/tests/language/language_dart2js.status
index 5dcf7155756f4efe52ed714bddc067d9dab987fe..4bd75671d3c83f124e8c08eb17e409e58cceb8f8 100644
--- a/tests/language/language_dart2js.status
+++ b/tests/language/language_dart2js.status
@@ -179,7 +179,7 @@ malbounded_type_test_test/04: Fail # Issue 14121
 malbounded_type_test2_test: Fail # Issue 14121
 default_factory2_test/01: Fail # Issue 14121
 
-[ $compiler == dart2js && $unchecked ]
+[ $compiler == dart2js && ! $checked ]
 type_checks_in_factory_method_test: RuntimeError # Issue 12746
 assertion_test: RuntimeError # Issue 12748
 generic_test: RuntimeError, OK
@@ -191,7 +191,7 @@ positional_parameters_type_test/01: MissingRuntimeError, OK
 positional_parameters_type_test/02: MissingRuntimeError, OK
 issue13474_test: RuntimeError, OK
 
-[ $compiler == dart2js && $unchecked && $minified ]
+[ $compiler == dart2js && ! $checked && $minified ]
 f_bounded_quantification5_test: Fail, OK # Issue 12605
 
 [ $compiler == dart2js && $minified ]