GHC.Prim use virtual-modules

Stop the GHC.Prim madness with `virtual-module` support from cabal.
Needs https://github.com/haskell/cabal/pull/4875.

Bumps submodule libraries/Cabal to include the necessary logic for `virtual-module`.

Reviewers: bgamari

Reviewed By: bgamari

Subscribers: rwbarton, thomie

Differential Revision: https://phabricator.haskell.org/D4179