Does not work with GHCJS

[andrewthad]

This does not work with GHCJS because of it uses the c ffi. Not sure if there's a great workaround for this.

[hvr]

What I'm struggling with is coming up with an answer on whether it makes sense for JavaScript targets to represent strings as UTF8 encoded ByteArray#s or whether it's more efficient to instead use JS' native String objects to represent strings (but which due to historical reasons and lack of foresight are stuck w/ an UTF-16 encoding for the foreseeable future), as JS engines are heavily optimized for that.

The answer to this question decides between two quite different paths...