gnu: Add ghc-annotated-wl-pprint.

* gnu/packages/haskell.scm (ghc-annotated-wl-pprint): New variable.

gnu: ghc-split: Update dependencies.

* gnu/packages/haskell.scm (ghc-split): Update package dependencies for
  compatibility with new GHC.  Replicate Cabal-file patch from Hackage.

gnu: Add ghc-quickcheck-unicode.

* gnu/packages/haskell.scm (ghc-quickcheck-unicode): New variable.

gnu: Add ghc-xml.

* gnu/packages/haskell.scm (ghc-xml): New variable.

gnu: Add ghc-logict.

* gnu/packages/haskell.scm (ghc-logict): New variable.

gnu: Add ghc-pcre-light.

* gnu/packages/haskell.scm (ghc-pcre-light): New variable.

gnu: Add ghc-generic-deriving.

* gnu/packages/haskell.scm (ghc-generic-deriving): New variable.

gnu: Add ghc-safe.

* gnu/packages/haskell.scm (ghc-safe): New variable.

gnu: Add ghc-appar.

* gnu/packages/haskell.scm (ghc-appar): New variable.

gnu: Add ghc-regex-base.

* gnu/packages/haskell.scm (ghc-regex-base): New variable.

gnu: Add ghc-hspec.

* gnu/packages/haskell.scm (ghc-hspec): New variable.

gnu: Add hspec-discover.

* gnu/packages/haskell.scm (hspec-discover): New variable.

gnu: Add ghc-hspec-meta.

* gnu/packages/haskell.scm (ghc-hspec-meta): New variable.

gnu: Add ghc-hspec-core.

* gnu/packages/haskell.scm (ghc-hspec-core): New variable.

gnu: Add ghc-hspec-expectations.

* gnu/packages/haskell.scm (ghc-hspec-expectations): New variable.

gnu: Add ghc-silently.

* gnu/packages/haskell.scm (ghc-silently): New variable.

gnu: Add ghc-temporary.

* gnu/packages/haskell.scm (ghc-temporary): New variable.

gnu: Add ghc-exceptions.

* gnu/packages/haskell.scm (ghc-exceptions): New variable.

gnu: Add ghc-transformers-compat.

* gnu/packages/haskell.scm (ghc-transformers-compat): New variable.

gnu: Add ghc-quickcheck-io.

* gnu/packages/haskell.scm (ghc-quickcheck-io): Add variable.