Make compatible with GHC 8.4.1

There was ambiguity with (<>) both in a dependency and in our pretty
printing functionality.

Author: Mistral Contrastin

fortran-src.cabal

@@ -26,7 +26,7 @@ executable fortran-src
     mtl >= 2.2 && < 3,
     array >= 0.5 && < 0.6,
     uniplate >= 1.6 && < 2,
-    GenericPretty >= 1.2 && < 2,
+    GenericPretty >= 1.2.2 && < 2,
     pretty >= 1.1 && < 2,
     containers >= 0.5 && < 0.6,
     text >= 1.2 && < 2,

src/Language/Fortran/PrettyPrint.hs

@@ -8,7 +8,7 @@ module Language.Fortran.PrettyPrint where
 import Data.Maybe (isJust, isNothing)
 import Data.List (foldl')
 
-import Prelude hiding (EQ,LT,GT)
+import Prelude hiding (EQ,LT,GT,(<>))
 
 import Language.Fortran.AST
 import Language.Fortran.ParserMonad