Skip FE tests under dart2js + fast-startup (which doesn't support dart:mirrors)

pkg/pkg.status

Index: pkg/pkg.status
diff --git a/pkg/pkg.status b/pkg/pkg.status
index ee9fe4a155fd32a154f2f1f0ef4a03cf605d3e83..2488eeaccaef37128c1036d1d41a3e7b8adec178 100644
--- a/pkg/pkg.status
+++ b/pkg/pkg.status
@@ -57,6 +57,9 @@ typed_data/test/typed_buffers_test/01: Fail # Not supporting Int64List, Uint64Li
 front_end/test/memory_file_system_test: CompileTimeError # Issue 23773
 front_end/test/physical_file_system_test: SkipByDesign # Uses dart:io
 
+[ $compiler == dart2js && $fast_startup ]
+front_end/test/*: SkipByDesign # Tests written with dart:mirrors.
+
 [ $compiler == dart2js && $builder_tag != dart2js_analyzer ]
 analyzer/test/*: Skip # Issue 26813
 analyzer/tool/*: Skip # Issue 26813