be2b1d5d2a
Given that we now only use Workers when `postMessage` transfers are supported, there's really no point in trying to send a "test" message *without* transfers present. Hence, if `postMessage` transfers are not supported by the browser, we'll now fallback to "fake" Workers immediately instead. The comment about Opera is also removed, since it was originally added back in PR 983 and mentions Opera `11.60` [which was released in 2011](https://en.wikipedia.org/wiki/History_of_the_Opera_web_browser#Version_11).