Build closures of haskell libraries

[facundominguez]

This likely requires using cc_haskell_import or writing some adapter rule for the purpose. As it stands, haskell_library doesn't yield the shared library in the outputs.

cc_haskell_import was not forwarding some runfiles last time I tried it, so it may need some fixing. This issue is about coming with a reasonable story for making closures of these libraries.