Fix broken test of platform version
Fix broken test of platform version

The version check regexp expected that additional info was stripped. The
dartdoc for Platform.version says that the version is what is before the
first space if any.

R=ricow@google.com
BUG=

Review URL: https://codereview.chromium.org//953323002

git-svn-id: c93d8a2297af3b929165606efe145742a534bc71@44021 260f80e4-7a28-3924-810f-c04153c831b5

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