Remove LambdaCase and MultiWayIf

hackage-security/src/Hackage/Security/Util/FileLock.hsc

@@ -1,7 +1,5 @@
 {-# LANGUAGE CPP #-}
 {-# LANGUAGE InterruptibleFFI #-}
-{-# LANGUAGE LambdaCase #-}
-{-# LANGUAGE MultiWayIf #-}
 {-# LANGUAGE DeriveDataTypeable #-}
 
 -- | This compat module can be removed once base-4.10 (ghc-8.2) is the minimum
@@ -142,12 +140,12 @@ lockImpl h ctx mode block = do
  -- not an error", however e.g. Windows 10 doesn't accept maximum possible
  -- value (a pair of MAXDWORDs) for mysterious reasons. Work around that by
  -- trying 2^32-1.
- fix $ \retry -> c_LockFileEx wh flags 0 0xffffffff 0x0 ovrlpd >>= \case
+ fix $ \retry -> c_LockFileEx wh flags 0 0xffffffff 0x0 ovrlpd >>= \b -> case b of
  True -> return True
- False -> getLastError >>= \err -> if
- | not block && err == #{const ERROR_LOCK_VIOLATION} -> return False
- | err == #{const ERROR_OPERATION_ABORTED} -> retry
- | otherwise -> failWith ctx err
+ False -> getLastError >>= \err -> case () of
+ () | not block && err == #{const ERROR_LOCK_VIOLATION} -> return False
+  | err == #{const ERROR_OPERATION_ABORTED} -> retry
+  | otherwise -> failWith ctx err
  where
  sizeof_OVERLAPPED = #{size OVERLAPPED}
 
@@ -169,12 +167,12 @@ lockImpl :: Handle -> String -> LockMode -> Bool -> IO Bool
 lockImpl h ctx mode block = do
  FD{fdFD = fd} <- handleToFd h
  let flags = cmode .|. (if block then 0 else #{const LOCK_NB})
- fix $ \retry -> c_flock fd flags >>= \case
+ fix $ \retry -> c_flock fd flags >>= \n -> case n of
  0 -> return True
- _ -> getErrno >>= \errno -> if
- | not block && errno == eWOULDBLOCK -> return False
- | errno == eINTR -> retry
- | otherwise -> ioException $ errnoToIOError ctx errno (Just h) Nothing
+ _ -> getErrno >>= \errno -> case () of
+ () | not block && errno == eWOULDBLOCK -> return False
+  | errno == eINTR -> retry
+  | otherwise -> ioException $ errnoToIOError ctx errno (Just h) Nothing
  where
  cmode = case mode of
  SharedLock -> #{const LOCK_SH}