Use reallyUnsafePtrEquality# for compatibility

...with GHC < 9.4.

Author: sjakobi

Data/HashMap/Internal.hs

@@ -1869,7 +1869,7 @@ difference = go 0
                       Empty -> goDA i (i1 + 1) nextB1' bResult (nChanges + 1)
                       st -> do
                         A.write mary i st
-                        let same = I# (Exts.reallyUnsafePtrEquality st st1)
+                        let same = I# (Exts.reallyUnsafePtrEquality# st st1)
                         let nChanges' = nChanges + (1 - same)
                         goDA (i + 1) (i1 + 1) nextB1' (bResult .|. m) nChanges'
               where