Fix warnings in utils/UniqSet

compiler/utils/UniqSet.lhs

@@ -9,29 +9,21 @@ Based on @UniqFMs@ (as you would expect).
 Basically, the things need to be in class @Uniquable@.
 
 \begin{code}
-{-# OPTIONS -w #-}
--- The above warning supression flag is a temporary kludge.
--- While working on this module you are encouraged to remove it and fix
--- any warnings in the module. See
---     http://hackage.haskell.org/trac/ghc/wiki/Commentary/CodingStyle#Warnings
--- for details
-
 module UniqSet (
         UniqSet,    -- abstract type: NOT
 
         mkUniqSet, uniqSetToList, emptyUniqSet, unitUniqSet,
-	addOneToUniqSet, addListToUniqSet, delOneFromUniqSet, delListFromUniqSet,
+        addOneToUniqSet, addListToUniqSet,
+        delOneFromUniqSet, delListFromUniqSet,
         unionUniqSets, unionManyUniqSets, minusUniqSet,
         elementOfUniqSet, mapUniqSet, intersectUniqSets,
         isEmptyUniqSet, filterUniqSet, sizeUniqSet, foldUniqSet,
         elemUniqSet_Directly, lookupUniqSet, hashUniqSet
     ) where
 
-#include "HsVersions.h"
-
-import Maybes		( maybeToBool )
+import Maybes
 import UniqFM
-import Unique		( Unique, Uniquable(..) )
+import Unique
 
 #if ! OMIT_NATIVE_CODEGEN
 #define IF_NCG(a) a
@@ -86,7 +78,7 @@ unionUniqSets :: UniqSet a -> UniqSet a -> UniqSet a
 unionUniqSets (MkUniqSet set1) (MkUniqSet set2) = MkUniqSet (plusUFM set1 set2)
 
 unionManyUniqSets :: [UniqSet a] -> UniqSet a
-	-- = foldr unionUniqSets emptyUniqSet ss
+-- = foldr unionUniqSets emptyUniqSet ss
 unionManyUniqSets []     = emptyUniqSet
 unionManyUniqSets [s]    = s
 unionManyUniqSets (s:ss) = s `unionUniqSets` unionManyUniqSets ss