Mark standalone/io/observatory_test as crash on dart2js
Mark standalone/io/observatory_test as crash on dart2js

This started happening after landing new io resource metadata tracking in:
https://github.com/dart-lang/sdk/commit/06ab2bdbdda2ad1696a842ea44d8fd0d38106f7f

I created issue 24291 to track this

BUG=

Review URL: https://codereview.chromium.org//1330603003 .

dartino/dart-sdk,dart-archive/dart-sdk,dart-lang/sdk,dart-archive/dart-sdk,dartino/dart-sdk,dart-archive/dart-sdk,dartino/dart-sdk,dart-archive/dart-sdk,dartino/dart-sdk,dartino/dart-sdk,dart-lang/sdk,dart-archive/dart-sdk,dartino/dart-sdk,dart-lang/sdk,dartino/dart-sdk,dart-archive/dart-sdk,dartino/dart-sdk,dart-lang/sdk,dart-archive/dart-sdk,dart-archive/dart-sdk,dart-archive/dart-sdk,dart-lang/sdk,dart-lang/sdk,dart-lang/sdk,dart-lang/sdk,dartino/dart-sdk