Add a test that wptrunner fails when it should.

tests/wpt/metadata/MANIFEST.json

@@ -14245,6 +14245,9 @@
       {
         "url": "/http/content_length.html"
       },
+      {
+        "url": "/infrastructure/failing-test.html"
+      },
       {
         "url": "/js/builtins/Array.DefineOwnProperty.html"
       },
@@ -17763,6 +17766,6 @@
     "deleted": [],
     "items": {}
   },
-  "rev": "badfd02aa085e25bd79f18902afbafcc8bc884b5",
+  "rev": "5bff693a497f200800d6d0dd6e3cc3556cc00bbe",
   "url_base": "/"
 }

tests/wpt/web-platform-tests

@@ -1 +1 @@
-Subproject commit badfd02aa085e25bd79f18902afbafcc8bc884b5
+Subproject commit 5bff693a497f200800d6d0dd6e3cc3556cc00bbe