cc_haskell_import should work with haskell_binary

[mboes]

Given a haskell_library, it's currently possible to export it for consumption by the CC rules using cc_haskell_import. But a haskell_binary sometimes looks pretty similar to a haskell_library. It might not have a ghc-pkg database entry associated to it, but if it's compiled with -dynamic -pie, then it looks and smells so much like any odd shared library that the file command would be fooled. We use this property in sparkle, where we routinely compile PIE binaries and then dlopen() them like any other shared object.

This problem perhaps points to a deeper one: HaskellPackageInfo is likely too monolithic. It could make sense to split it out into multiple providers focused on specific aspects of the produced artifact, much like the Go rules do (GoLibrary, GoArchive, GoArchiveData etc). See https://github.com/bazelbuild/rules_go/blob/master/go/providers.rst.

[mboes]

The original problem was fixed pretty much entirely, as a side effect of #186. There does remain another problem, which is that cc_haskell_import should ensure the result is always named as a library. Otherwise cc_* rules won't accept the output in the srcs attribute.