Remove some compat cruft from Core.hs

src/Constrained/Core.hs

@@ -1,4 +1,3 @@
-{-# LANGUAGE CPP #-}
 {-# LANGUAGE FlexibleInstances #-}
 {-# LANGUAGE GADTs #-}
 {-# LANGUAGE ImportQualifiedPost #-}
@@ -7,9 +6,6 @@
 {-# LANGUAGE StandaloneDeriving #-}
 {-# LANGUAGE TypeApplications #-}
 {-# LANGUAGE TypeOperators #-}
--- Arbitrary NonEmpty
--- TOOD: fixme by bumping QuickCheck to 3.0 when it's released
-{-# OPTIONS_GHC -Wno-orphans #-}
 
 -- | This is a collection of relatively core concepts that are re-used
 -- throughout the codebase.
@@ -40,12 +36,6 @@ import Data.Set (Set)
 import Data.Set qualified as Set
 import Data.Typeable
 
--- Orphan instance for old QuickCheck versions
-#if !MIN_VERSION_QuickCheck(2, 17, 0)
-import Data.List.NonEmpty qualified as NE
-import Test.QuickCheck (Arbitrary (..), NonEmptyList (NonEmpty))
-#endif
-
 -- Variables --------------------------------------------------------------
 
 -- | Typed, optionally named, variables
@@ -140,9 +130,3 @@ instance Typeable c => Show (Evidence c) where
 unionWithMaybe :: (a -> a -> a) -> Maybe a -> Maybe a -> Maybe a
 unionWithMaybe f ma ma' = (f <$> ma <*> ma') <|> ma <|> ma'
 
-#if !MIN_VERSION_QuickCheck(2, 17, 0)
-instance Arbitrary a => Arbitrary (NonEmpty a) where
-  arbitrary = do
-    NonEmpty xs <- arbitrary
-    pure (NE.fromList xs)
-#endif

src/Constrained/Test.hs

@@ -1,3 +1,4 @@
+{-# LANGUAGE CPP #-}
 {-# LANGUAGE DataKinds #-}
 {-# LANGUAGE FlexibleContexts #-}
 {-# LANGUAGE FlexibleInstances #-}
@@ -441,3 +442,12 @@ instance QC.Arbitrary TestableFn where
       , TestableFn $ AppendW @Int
       ]
   shrink _ = []
+
+-- Cruft ------------------------------------------------------------------
+
+#if !MIN_VERSION_QuickCheck(2, 17, 0)
+instance Arbitrary a => Arbitrary (NonEmpty a) where
+  arbitrary = do
+    NonEmpty xs <- arbitrary
+    pure (NE.fromList xs)
+#endif