fix 8.6

Author: wz1000

ghcide/src/Development/IDE/Spans/AtPoint.hs

@@ -2,6 +2,8 @@
 -- SPDX-License-Identifier: Apache-2.0
 
 {-# LANGUAGE GADTs #-}
+{-# LANGUAGE CPP #-}
+#include "ghc-api-version.h"
 
 -- | Gives information about symbols at a given point in DAML files.
 -- These are all pure functions that should execute quickly.
@@ -253,7 +255,11 @@ typeLocationsAtPoint hiedb lookupModule _ideOptions pos (HAR _ ast _ _ hieKind)
             where ni = nodeInfo x
           getTypes ts = flip concatMap (unfold ts) $ \case
             HTyVarTy n -> [n]
+#if MIN_GHC_API_VERSION(8,8,0)
             HAppTy a (HieArgs xs) -> getTypes (a : map snd xs)
+#else
+            HAppTy a b -> getTypes [a,b]
+#endif
             HTyConApp tc (HieArgs xs) -> ifaceTyConName tc : getTypes (map snd xs)
             HForAllTy _ a -> getTypes [a]
             HFunTy a b -> getTypes [a,b]