Move --with-ghc Setup.lhs into Scripts, use standard Setup.lhs at top level

Setup.lhs

@@ -1,19 +1,5 @@
 #!/usr/bin/env runhaskell
 > module Main where
 > import Distribution.Simple
-> import Distribution.Setup   ( ConfigFlags (..) )
-> import System.Directory     ( findExecutable )
-> 
 > main :: IO ()
-> main = defaultMainWithHooks (defaultUserHooks { postConf = defaultPostConf })
+> main = defaultMainWithHooks defaultUserHooks
->     where defaultPostConf args flags lbi {- xx -}
->               = do args' <- fmap (args++) (configToArgs flags)
->                    (postConf defaultUserHooks) args' flags lbi {- xx -}
-> 
-> configToArgs :: ConfigFlags -> IO [String]
-> configToArgs (ConfigFlags { configHcPath = Just hcPath })
->     = do exec <- findExecutable hcPath
->          case exec of
->            Just realPath -> return ["--with-ghc="++realPath]
->            Nothing -> return ["--with-ghc="++hcPath]
-> configToArgs _ = return []

scripts/Setup-with-ghc.lhs

@@ -0,0 +1,20 @@
+#!/usr/bin/env runhaskell
+> module Main where
+> import Distribution.Simple
+> import Distribution.Setup   ( ConfigFlags (..) )
+> import System.Directory     ( findExecutable )
+> 
+> main :: IO ()
+> main = defaultMainWithHooks (defaultUserHooks { postConf = defaultPostConf })
+>     where defaultPostConf args flags lbi {- xx -}
+>               = do args' <- fmap (args++) (configToArgs flags)
+>                    (postConf defaultUserHooks) args' flags lbi {- xx -}
+> 
+> -- need to pass with-ghc arg onto ./configure for non-standard ghcs
+> configToArgs :: ConfigFlags -> IO [String]
+> configToArgs (ConfigFlags { configHcPath = Just hcPath })
+>     = do exec <- findExecutable hcPath
+>          case exec of
+>            Just realPath -> return ["--with-ghc="++realPath]
+>            Nothing -> return ["--with-ghc="++hcPath]
+> configToArgs _ = return []