[webkit-dev] JavaScriptCore and ES6

[Anne van Kesteren]

In general I think versioning is a bad idea, but out-of-band is even
worse. We'd have to change Web Workers (both constructors and
importScripts() would need to take some kind version-related
information) and everyone on the platform would instead of simply
using <script> have to resort back to specifying the type attribute
again. We just got rid of that!