Fix AMP warnings

Cabal/Distribution/Compat/ReadP.hs

@@ -69,9 +69,9 @@ module Distribution.Compat.ReadP
   )
  where
 
-import Control.Monad( MonadPlus(..), liftM2, ap )
+import Control.Monad( MonadPlus(..), liftM, liftM2, ap )
 import Data.Char (isSpace)
-import Control.Applicative (Applicative(..))
+import Control.Applicative (Applicative(..), Alternative(empty, (<|>)))
 
 infixr 5 +++, <++
 
@@ -89,7 +89,7 @@ data P s a
 -- Monad, MonadPlus
 
 instance Functor (P s) where
-  fmap f x = x >>= return . f
+  fmap = liftM
 
 instance Applicative (P s) where
   pure = return
@@ -106,6 +106,10 @@ instance Monad (P s) where
 
   fail _ = Fail
 
+instance Alternative (P s) where
+      empty = mzero
+      (<|>) = mplus
+
 instance MonadPlus (P s) where
   mzero = Fail
 

Cabal/Distribution/Simple/BuildTarget.hs

@@ -55,7 +55,7 @@ import Data.Either
          ( partitionEithers )
 import qualified Data.Map as Map
 import Control.Monad
-import Control.Applicative (Applicative(..))
+import Control.Applicative (Applicative(..), Alternative(..))
 import qualified Distribution.Compat.ReadP as Parse
 import Distribution.Compat.ReadP
          ( (+++), (<++) )
@@ -745,6 +745,10 @@ data MatchError = MatchErrorExpected String String
   deriving (Show, Eq)
 
 
+instance Alternative Match where
+      empty = mzero
+      (<|>) = mplus
+
 instance MonadPlus Match where
   mzero = matchZero
   mplus = matchPlus