Cabal revisions of llvm-hs-5.1.2

Hackage metadata revisions edit the .cabal file after upload; each diff below is one revision.

 name: llvm-hs version: 5.1.2+x-revision: 1 license: BSD3 license-file: LICENSE author: Anthony Cowley, Stephen Diehl, Moritz Kiefer <moritz.kiefer@purelyfunctional.org>, Benjamin S. Scarlet  custom-setup   setup-depends: base-               , Cabal+               , Cabal <2                , containers  library