Drop duplication of module names in moduleFilesOracle.
Drop duplication of module names in moduleFilesOracle.

See #210.

sdiehl/ghc,snowleopard/shaking-up-ghc,sdiehl/ghc,sdiehl/ghc,sdiehl/ghc,sdiehl/ghc,bgamari/shaking-up-ghc,izgzhen/hadrian,snowleopard/hadrian,sdiehl/ghc,sdiehl/ghc