Async exceptions are now masked during the finalizer. Thanks again, David!

In addition to my GHC fork [1], I’ve now also made a patch file [2], which should apply cleanly on any recent version of HEAD. Apparently it’s rather tricky to initialise a GitHub-cloned GHC fork, as I’ve discovered. The patch file should make it easier to play around with the extension.

[1] https://github.com/mcschroeder/ghc
[2] https://gist.github.com/mcschroeder/921eb3d50b2576a3e552

Cheers,
Michael