Strict.updateOrSnocWithKey: Use Array.snoc (#409)

Fixes #363.

Author: sjakobi

Data/HashMap/Internal/Strict.hs

@@ -742,13 +742,8 @@ updateOrSnocWithKey :: Eq k => (k -> v -> v -> v) -> k -> v -> A.Array (Leaf k v
 updateOrSnocWithKey f k0 v0 ary0 = go k0 v0 ary0 0 (A.length ary0)
   where
     go !k v !ary !i !n
-        | i >= n = A.run $ do
-            -- Not found, append to the end.
-            mary <- A.new_ (n + 1)
-            A.copy ary 0 mary 0 n
-            let !l = v `seq` L k v
-            A.write mary n l
-            return mary
+        -- Not found, append to the end.
+        | i >= n = A.snoc ary $! L k $! v
         | otherwise = case A.index ary i of
             (L kx y) | k == kx   -> let !v' = f k v y in A.update ary i (L k v')
                      | otherwise -> go k v ary (i+1) n