Restablish compatibility with GHC 7.4.1

As of now, this package has been verified to work with GHC 7.4.x, GHC
7.6.x and GHC HEAD.

Signed-off-by: Herbert Valerio Riedel <hvr@gnu.org>

Data/Array/Base.hs

@@ -32,6 +32,9 @@ import GHC.ST           ( ST(..), runST )
 import GHC.Base
 import GHC.Ptr          ( Ptr(..), FunPtr(..), nullPtr, nullFunPtr )
 import GHC.Stable       ( StablePtr(..) )
+#if !MIN_VERSION_base(4,6,0)
+import GHC.Exts         ( Word(..) )
+#endif
 import GHC.Int          ( Int8(..),  Int16(..),  Int32(..),  Int64(..) )
 import GHC.Word         ( Word8(..), Word16(..), Word32(..), Word64(..) )
 import GHC.IO           ( stToIO )

array.cabal

@@ -39,7 +39,7 @@ library
       Trustworthy,
       UnboxedTuples,
       UnliftedFFITypes
-  build-depends: base >= 4.5 && < 5
+  build-depends: base >= 4.5 && < 4.8
   ghc-options: -Wall
   exposed-modules:
       Data.Array