unfoildrN{,M} now uses Unknown allocation strategy

Before functions allocated array of maximum size immediately. This is problem in
case when attacker controls size parameter and could lead to DoS. It's also
problem when size parameter is just a limit vector is usually shorter. Usual
doubling strategy looks more conservative in this function.

Fixes #301

Author: Shimuuar

vector/src/Data/Vector/Fusion/Bundle/Monadic.hs

@@ -664,7 +664,7 @@ unfoldrN n f = unfoldrNM n (return . f)
 -- | Unfold at most @n@ elements with a monadic function.
 unfoldrNM :: Monad m => Int -> (s -> m (Maybe (a, s))) -> s -> Bundle m u a
 {-# INLINE_FUSED unfoldrNM #-}
-unfoldrNM n f s = fromStream (S.unfoldrNM n f s) (Max (delay_inline max n 0))
+unfoldrNM n f s = fromStream (S.unfoldrNM n f s) Unknown
 
 -- | Unfold exactly @n@ elements
 --