test: report ERROR wpt test results
When a wpt test file is exited for uncaught error, its result should be
recorded in the wptreport.json
and uploaded to wpt.fyi.
For instance, html/webappapis/timers/evil-spec-example.any.js
is
exited for uncaught error in Node.js but it shows as "MISSING" at
https://wpt.fyi/results/html/webappapis/timers?label=master&label=experimental&product=chrome&product=node.js&aligned.