Build ghci library in Stage0
Build ghci library in Stage0

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