Fix T12504
Fix T12504

This had an extra_files directive, which does not exist in ghc-8.0, from
cherry-picking.

GaloisInc/halvm-ghc,GaloisInc/halvm-ghc,GaloisInc/halvm-ghc,GaloisInc/halvm-ghc,GaloisInc/halvm-ghc,GaloisInc/halvm-ghc,GaloisInc/halvm-ghc