Update mirror tests to new mixin application syntax.

tests/lib/lib.status

Index: tests/lib/lib.status
diff --git a/tests/lib/lib.status b/tests/lib/lib.status
index 9a8cd8d9b6aa39f7a510d6951b1df2052b28ea06..a3e7f4cf1e0c29e54a5f53cf61f2c8a549f62d90 100644
--- a/tests/lib/lib.status
+++ b/tests/lib/lib.status
@@ -236,6 +236,12 @@ mirrors/invoke_named_test/none: Fail # http://dartbug.com/13612
 mirrors/generic_f_bounded_mixin_application_test: Fail # Issue 14116
 mirrors/generic_interface_test/none: Fail # Inexpressible in multitest
 
+# Will be fixed by next roll?
+mirrors/typedef_metadata_test: Fail
+mirrors/mixin_test: Fail
+mirrors/mixin_application_test/none: Fail
+mirrors/generic_mixin_applications_test: Fail
+
 [ $compiler == none && $runtime == dartium ]
 async/schedule_microtask5_test: Pass, Timeout # Issue 13719: Please triage this failure.
 async/timer_cancel2_test: Pass, Timeout # Issue 13719: Please triage this failure.