Add dart2js-strong entry in pkg.status

TBR=sra@google.com

Change-Id: Id5bf90f1a614ecd3f4816bed5d9d0f12b7ee4953
Reviewed-on: https://dart-review.googlesource.com/63263
Reviewed-by: Sigmund Cherem <sigmund@google.com>
Reviewed-by: Stephen Adams <sra@google.com>
Commit-Queue: Sigmund Cherem <sigmund@google.com>
diff --git a/pkg/pkg.status b/pkg/pkg.status
index 4cd6b20..c0e2565 100644
--- a/pkg/pkg.status
+++ b/pkg/pkg.status
@@ -233,6 +233,9 @@
 [ $compiler == dart2js && $csp ]
 mutation_observer: Skip # This test cannot run under CSP because it is injecting a JavaScript polyfill
 
+[ $compiler == dart2js && $strong ]
+status_file/test/status_expression_dnf_test: RuntimeError # not strong-clean
+
 [ $compiler == dart2js && ($runtime == chrome || $runtime == ff) ]
 async/test/stream_zip_test: SkipSlow # Times out. Issue 22050
 collection/test/unmodifiable_collection_test: SkipSlow # Times out. Issue 22050