Runtime Haskell interpreter

#8pprErrMsgBagWithLoc does not exist in GHC 7.4.1

Hi! I think there's an issue either with the preprocessor directives in the imports of Hint.GHC, or with the dependencies of Hint itself. pprErrMsgBagWithLoc is not exported from ErrUtils before GHC 7.4.2. :)