Remove old GHCJS support

PR #137 included #ifdef __GHCJS__ for the old GHCJS.

ghcjs-base >= 0.8 is for the new GHC JS backend only.

If we need to update support for the old GHCJS version in the future we will need to create a branch from the 0.2.0.3 tag.

JavaScript/Web/AnimationFrame.hs

@@ -2,7 +2,6 @@
 {-# LANGUAGE JavaScriptFFI #-}
 {-# LANGUAGE InterruptibleFFI #-}
 {-# LANGUAGE DeriveDataTypeable #-}
-{-# LANGUAGE CPP #-}
 
 {- |
      Animation frames are the browser's mechanism for smooth animation.
@@ -65,11 +64,7 @@ cancelAnimationFrame h = js_cancelAnimationFrame h
 
 foreign import javascript unsafe "(() => { return { handle: null, callback: null }; })"
   js_makeAnimationFrameHandle :: IO AnimationFrameHandle
-#ifdef __GHCJS__
-foreign import javascript unsafe "(() => { return { handle: null, callback: $1 }; })"
-#else
 foreign import javascript unsafe "(($1) => { return { handle: null, callback: $1 }; })"
-#endif
   js_makeAnimationFrameHandleCallback :: JSVal -> IO AnimationFrameHandle
 foreign import javascript unsafe "h$animationFrameCancel"
   js_cancelAnimationFrame :: AnimationFrameHandle -> IO ()