Get rid of more CPP in cmm/ and codeGen/

This removes a bunch of unnecessary includes of `HsVersions.h` along
with unnecessary CPP (e.g., due to checking for DEBUG which can be
achieved by looking at `debugIsOn`)

Signed-off-by: Michal Terepeta <michal.terepeta@gmail.com>

Test Plan: ./validate

Reviewers: bgamari, simonmar

Reviewed By: bgamari

Subscribers: rwbarton, thomie, carter

Differential Revision: https://phabricator.haskell.org/D4462

4 files changed, 8 insertions, 17 deletions

diff --git a/compiler/cmm/Cmm.hs b/compiler/cmm/Cmm.hs
index 9f832731b1..50d48afb38 100644
--- a/compiler/cmm/Cmm.hs
+++ b/compiler/cmm/Cmm.hs
@@ -1,5 +1,5 @@
 -- Cmm representations using Hoopl's Graph CmmNode e x.
-{-# LANGUAGE CPP, GADTs #-}
+{-# LANGUAGE GADTs #-}
 
 module Cmm (
      -- * Cmm top-level datatypes
diff --git a/compiler/cmm/CmmExpr.hs b/compiler/cmm/CmmExpr.hs
index bae5a739ca..946e146f9e 100644
--- a/compiler/cmm/CmmExpr.hs
+++ b/compiler/cmm/CmmExpr.hs
@@ -1,5 +1,4 @@
 {-# LANGUAGE BangPatterns #-}
-{-# LANGUAGE CPP #-}
 {-# LANGUAGE FlexibleContexts #-}
 {-# LANGUAGE FlexibleInstances #-}
 {-# LANGUAGE MultiParamTypeClasses #-}
diff --git a/compiler/cmm/MkGraph.hs b/compiler/cmm/MkGraph.hs
index d9f140254c..70229d067d 100644
--- a/compiler/cmm/MkGraph.hs
+++ b/compiler/cmm/MkGraph.hs
@@ -1,4 +1,4 @@
-{-# LANGUAGE BangPatterns, CPP, GADTs #-}
+{-# LANGUAGE BangPatterns, GADTs #-}
 
 module MkGraph
   ( CmmAGraph, CmmAGraphScoped, CgStmt(..)
@@ -21,7 +21,7 @@ module MkGraph
   )
 where
 
-import GhcPrelude (($),Int,Bool,Eq(..)) -- avoid importing (<*>)
+import GhcPrelude hiding ( (<*>) ) -- avoid importing (<*>)
 
 import BlockId
 import Cmm
@@ -37,10 +37,7 @@ import ForeignCall
 import OrdList
 import SMRep (ByteOff)
 import UniqSupply
-
-import Control.Monad
-import Data.List
-import Data.Maybe
+import Util
 
 
 -----------------------------------------------------------------------------
@@ -184,12 +181,10 @@ mkNop        :: CmmAGraph
 mkNop         = nilOL
 
 mkComment    :: FastString -> CmmAGraph
-#if defined(DEBUG)
--- SDM: generating all those comments takes time, this saved about 4% for me
-mkComment fs  = mkMiddle $ CmmComment fs
-#else
-mkComment _   = nilOL
-#endif
+mkComment fs
+  -- SDM: generating all those comments takes time, this saved about 4% for me
+  | debugIsOn = mkMiddle $ CmmComment fs
+  | otherwise = nilOL
 
 ---------- Assignment and store
 mkAssign     :: CmmReg  -> CmmExpr -> CmmAGraph
diff --git a/compiler/cmm/PprCmmDecl.hs b/compiler/cmm/PprCmmDecl.hs
index 9b3cecc3b8..9dd2332b67 100644
--- a/compiler/cmm/PprCmmDecl.hs
+++ b/compiler/cmm/PprCmmDecl.hs
@@ -1,5 +1,3 @@
-{-# LANGUAGE CPP #-}
-
 ----------------------------------------------------------------------------
 --
 -- Pretty-printing of common Cmm types
@@ -54,7 +52,6 @@ import System.IO
 
 -- Temp Jan08
 import SMRep
-#include "../includes/rts/storage/FunTypes.h"
 
 
 pprCmms :: (Outputable info, Outputable g)