Support GHCJS compilation

Is your feature request related to a problem? Please describe. GHCJS cannot compile accelerate.

Describe the solution you'd like GHCJS to successfully compile accelerate.

Describe alternatives you've considered Don't use accelerate.

Additional context accelerate currently uses foreign C calls that fail under GHCJS. Additionally, the terminal-size dependency does not compile with GHCJS.

I'm not sure how practical it would be to support compilation under GHCJS, but it would make accelerate an even more backend agnostic framework for computation. With GHCJS, accelerate could run on the web, in addition to CPUs and GPUs.