do ryan suggested changes to make sure older ghc with -WCompat doesn't complain

Author: cartazio

Data/Vector.hs

@@ -342,7 +342,7 @@ instance Monad Vector where
   (>>=) = flip concatMap
 #if !(MIN_VERSION_base(4,13,0))
   {-# INLINE fail #-}
-  fail _= empty
+  fail = Fail.fail -- == \ _str -> empty
 #endif
 
 instance Fail.MonadFail Vector where