Update status file and test.

tests/lib/lib.status

Index: tests/lib/lib.status
diff --git a/tests/lib/lib.status b/tests/lib/lib.status
index a6284a2fce16a1d5ec63b579ded02e7ddefadfc6..3857327e92f462464ea156a71eadafa27b8cdb7a 100644
--- a/tests/lib/lib.status
+++ b/tests/lib/lib.status
@@ -274,6 +274,8 @@ async/future_or_non_strong_test: RuntimeError # Issue 28010
 async/future_or_strong_test: RuntimeError, OK
 
 [ $compiler == none && ($runtime == drt || $runtime == dartium) ]
+async/future_or_bad_type_test/implements: Pass # Issue 28084
+
 mirrors/initializing_formals_test/01: Fail # initializing formals are implicitly final as of Dart 1.21
 async/schedule_microtask6_test: Fail # Issue 10910
 async/timer_test: Fail, Pass # Issue 15487