[treat modules with no export declaration as only exporting 'main'
John Meacham <john@repetae.net>**20060211021250] hunk ./FrontEnd/HsParser.ly 136
->	| body						{ HsModule { hsModuleName = main_mod, hsModuleExports = Nothing, hsModuleImports = (fst $1), hsModuleDecls = (snd $1) } }
+>	| body						{ HsModule { hsModuleName = main_mod, hsModuleExports = Just [HsEVar (UnQual (HsIdent "main"))], hsModuleImports = (fst $1), hsModuleDecls = (snd $1) } }