Make Applicative a superclass of Monad

Summary:
This includes pretty much all the changes needed to make `Applicative`
a superclass of `Monad` finally. There's mostly reshuffling in the
interests of avoid orphans and boot files, but luckily we can resolve
all of them, pretty much. The only catch was that
Alternative/MonadPlus also had to go into Prelude to avoid this.

As a result, we must update the hsc2hs and haddock submodules.

Signed-off-by: Austin Seipp <austin@well-typed.com>

Test Plan: Build things, they might not explode horribly.

Reviewers: hvr, simonmar

Subscribers: simonmar

Differential Revision: https://phabricator.haskell.org/D13

3 files changed, 10 insertions, 1 deletions

diff --git a/compiler/utils/IOEnv.hs b/compiler/utils/IOEnv.hs
index 1db15537c7..8193beb87f 100644
--- a/compiler/utils/IOEnv.hs
+++ b/compiler/utils/IOEnv.hs
@@ -1,4 +1,5 @@
 {-# LANGUAGE DeriveDataTypeable, UndecidableInstances #-}
+{-# LANGUAGE CPP #-}
 
 --
 -- (c) The University of Glasgow 2002-2006
@@ -43,7 +44,9 @@ import System.IO.Unsafe ( unsafeInterleaveIO )
 import System.IO        ( fixIO )
 import Control.Monad
 import MonadUtils
+#if __GLASGOW_HASKELL__ < 709
 import Control.Applicative (Alternative(..))
+#endif
 
 ----------------------------------------------------------------------
 -- Defining the monad type
diff --git a/compiler/utils/Maybes.lhs b/compiler/utils/Maybes.lhs
index d9e1762a2f..8052b1d848 100644
--- a/compiler/utils/Maybes.lhs
+++ b/compiler/utils/Maybes.lhs
@@ -4,6 +4,7 @@
 %
 
 \begin{code}
+{-# LANGUAGE CPP #-}
 module Maybes (
         module Data.Maybe,
 
@@ -17,7 +18,9 @@ module Maybes (
 
         MaybeT(..)
     ) where
+#if __GLASGOW_HASKELL__ < 709
 import Control.Applicative
+#endif
 import Control.Monad
 import Data.Maybe
 
diff --git a/compiler/utils/Stream.hs b/compiler/utils/Stream.hs
index 47cdee0789..edb0b0c558 100644
--- a/compiler/utils/Stream.hs
+++ b/compiler/utils/Stream.hs
@@ -5,14 +5,17 @@
 -- Monadic streams
 --
 -- -----------------------------------------------------------------------------
-
+{-# LANGUAGE CPP #-}
 module Stream (
     Stream(..), yield, liftIO,
     collect, fromList,
     Stream.map, Stream.mapM, Stream.mapAccumL
   ) where
 import Control.Monad
+#if __GLASGOW_HASKELL__ < 709
 import Control.Applicative
+#endif
+
 
 -- |
 -- @Stream m a b@ is a computation in some Monad @m@ that delivers a sequence