Move needBuilder to src/Builder.hs.
Move needBuilder to src/Builder.hs.

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