Fix build-failure regression for base < 4.7

The `$>` operator definition is available only since base-4.7 which
unfortunately wasn't caught before release to Hackage (but has been
fixed up by a metadata-revision)

This commit introduces a `CompatPrelude` module which allows to reduce
the amount of CPP by ousting it to a central location, i.e. the new
`CompatPrelude` module. This pattern also tends to reduce the tricks
needed to silence unused import warnings.

Addresses #1119

1 files changed, 2 insertions, 1 deletions

diff --git a/haddock-library/src/Documentation/Haddock/Parser/Monad.hs b/haddock-library/src/Documentation/Haddock/Parser/Monad.hs
index fa46f536..7c73a168 100644
--- a/haddock-library/src/Documentation/Haddock/Parser/Monad.hs
+++ b/haddock-library/src/Documentation/Haddock/Parser/Monad.hs
@@ -29,7 +29,6 @@ import qualified Data.Text as T
 import           Data.Text                   ( Text )
 
 import           Control.Monad               ( mfilter )
-import           Data.Functor                ( ($>) )
 import           Data.String                 ( IsString(..) )
 import           Data.Bits                   ( Bits(..) )
 import           Data.Char                   ( ord )
@@ -37,7 +36,9 @@ import           Data.List                   ( foldl' )
 import           Control.Applicative as App
 
 import           Documentation.Haddock.Types ( Version )
+
 import           Prelude hiding (takeWhile)
+import           CompatPrelude
 
 -- | The only bit of information we really care about truding along with us
 -- through parsing is the version attached to a @\@since@ annotation - if