Drop GHC 8.0 compatibility

GHC 8.4.1 is out, so now GHC's support window only extends
back to GHC 8.2. This means we can delete gobs of code that were
only used for GHC 8.0 support. Hooray!

Test Plan: ./validate

Reviewers: bgamari, erikd, dfeuer

Reviewed By: bgamari, dfeuer

Subscribers: alexbiehl, dfeuer, rwbarton, thomie, carter

Differential Revision: https://phabricator.haskell.org/D4492

3 files changed, 2 insertions, 37 deletions

diff --git a/compiler/utils/Binary.hs b/compiler/utils/Binary.hs
index c3c8ae3ab7..447317ca47 100644
--- a/compiler/utils/Binary.hs
+++ b/compiler/utils/Binary.hs
@@ -79,14 +79,10 @@ import qualified Data.ByteString.Unsafe   as BS
 import Data.IORef
 import Data.Char                ( ord, chr )
 import Data.Time
-#if MIN_VERSION_base(4,10,0)
 import Type.Reflection
 import Type.Reflection.Unsafe
 import Data.Kind (Type)
 import GHC.Exts (TYPE, RuntimeRep(..), VecCount(..), VecElem(..))
-#else
-import Data.Typeable
-#endif
 import Control.Monad            ( when )
 import System.IO as IO
 import System.IO.Unsafe         ( unsafeInterleaveIO )
@@ -610,7 +606,6 @@ instance Binary (Bin a) where
 -- -----------------------------------------------------------------------------
 -- Instances for Data.Typeable stuff
 
-#if MIN_VERSION_base(4,10,0)
 instance Binary TyCon where
     put_ bh tc = do
         put_ bh (tyConPackage tc)
@@ -620,17 +615,7 @@ instance Binary TyCon where
         put_ bh (tyConKindRep tc)
     get bh =
         mkTyCon <$> get bh <*> get bh <*> get bh <*> get bh <*> get bh
-#else
-instance Binary TyCon where
-    put_ bh tc = do
-        put_ bh (tyConPackage tc)
-        put_ bh (tyConModule tc)
-        put_ bh (tyConName tc)
-    get bh =
-        mkTyCon3 <$> get bh <*> get bh <*> get bh
-#endif
 
-#if MIN_VERSION_base(4,10,0)
 instance Binary VecCount where
     put_ bh = putByte bh . fromIntegral . fromEnum
     get bh = toEnum . fromIntegral <$> getByte bh
@@ -781,17 +766,6 @@ instance Typeable a => Binary (TypeRep (a :: k)) where
 instance Binary SomeTypeRep where
     put_ bh (SomeTypeRep rep) = putTypeRep bh rep
     get = getSomeTypeRep
-#else
-instance Binary TypeRep where
-    put_ bh type_rep = do
-        let (ty_con, child_type_reps) = splitTyConApp type_rep
-        put_ bh ty_con
-        put_ bh child_type_reps
-    get bh = do
-        ty_con <- get bh
-        child_type_reps <- get bh
-        return (mkTyConApp ty_con child_type_reps)
-#endif
 
 -- -----------------------------------------------------------------------------
 -- Lazy reading/writing
diff --git a/compiler/utils/UniqFM.hs b/compiler/utils/UniqFM.hs
index f0cc197b71..2a9b806178 100644
--- a/compiler/utils/UniqFM.hs
+++ b/compiler/utils/UniqFM.hs
@@ -20,7 +20,6 @@ and ``addToUFM\_C'' and ``Data.IntMap.insertWith'' differ in the order
 of arguments of combining function.
 -}
 
-{-# LANGUAGE CPP #-}
 {-# LANGUAGE DeriveDataTypeable #-}
 {-# LANGUAGE GeneralizedNewtypeDeriving #-}
 {-# OPTIONS_GHC -Wall #-}
@@ -79,19 +78,16 @@ import Outputable
 import Data.List (foldl')
 
 import qualified Data.IntMap as M
-#if MIN_VERSION_containers(0,5,9)
 import qualified Data.IntMap.Merge.Lazy as M
 import Control.Applicative (Const (..))
 import qualified Data.Monoid as Mon
-#endif
 import qualified Data.IntSet as S
-import Data.Typeable
 import Data.Data
 import qualified Data.Semigroup as Semi
 
 
 newtype UniqFM ele = UFM (M.IntMap ele)
-  deriving (Data, Eq, Functor, Typeable)
+  deriving (Data, Eq, Functor)
   -- We used to derive Traversable and Foldable, but they were nondeterministic
   -- and not obvious at the call site. You can use explicit nonDetEltsUFM
   -- and fold a list if needed.
@@ -346,14 +342,10 @@ ufmToIntMap (UFM m) = m
 
 -- Determines whether two 'UniqFm's contain the same keys.
 equalKeysUFM :: UniqFM a -> UniqFM b -> Bool
-#if MIN_VERSION_containers(0,5,9)
 equalKeysUFM (UFM m1) (UFM m2) = Mon.getAll $ getConst $
       M.mergeA (M.traverseMissing (\_ _ -> Const (Mon.All False)))
                (M.traverseMissing (\_ _ -> Const (Mon.All False)))
                (M.zipWithAMatched (\_ _ _ -> Const (Mon.All True))) m1 m2
-#else
-equalKeysUFM (UFM m1) (UFM m2) = M.keys m1 == M.keys m2
-#endif
 
 -- Instances
 
diff --git a/compiler/utils/UniqMap.hs b/compiler/utils/UniqMap.hs
index 2dd3cd57ea..1bd51c2b38 100644
--- a/compiler/utils/UniqMap.hs
+++ b/compiler/utils/UniqMap.hs
@@ -54,12 +54,11 @@ import Outputable
 import Data.Semigroup as Semi ( Semigroup(..) )
 import Data.Coerce
 import Data.Maybe
-import Data.Typeable
 import Data.Data
 
 -- | Maps indexed by 'Uniquable' keys
 newtype UniqMap k a = UniqMap (UniqFM (k, a))
-    deriving (Data, Eq, Functor, Typeable)
+    deriving (Data, Eq, Functor)
 type role UniqMap nominal representational
 
 instance Semigroup (UniqMap k a) where