Fix size tracking in 'filterMapAuxInternal'

Because values are bound to 'sz' often in the many local functions
used in 'filterMapAuxInternal', some shadowing occured that
caused the size calculated to be incorrect. This commit renames
those variables to avoid collisions.

Data/HashMap/Base.hs

@@ -1295,30 +1295,30 @@ filterMapAuxInternal onLeaf onColl = go 0
     go !sz (Full ary) = filterA sz ary fullNodeMask
     go !sz (Collision h ary) = filterC sz ary h
 
-    filterA sz ary0 b0 =
+    filterA sze ary0 b0 =
         let !n = A.length ary0
         in runST $ do
             mary <- A.new_ n
-            step ary0 mary b0 0 0 1 n sz
+            step ary0 mary b0 0 0 1 n sze
       where
         step :: A.Array (Tree k v1) -> A.MArray s (Tree k v2)
              -> Bitmap -> Int -> Int -> Bitmap -> Int -> Int
              -> ST s (A.Sized (Tree k v2))
         step !ary !mary !b i !j !bi n !siz
             | i >= n = case j of
-                0 -> return (A.Sized siz Empty)
+                0 -> return $! A.Sized siz Empty
                 1 -> do
                     ch <- A.read mary 0
                     case ch of
-                      t | isLeafOrCollision t -> return (A.Sized siz t)
+                      t | isLeafOrCollision t -> return $! A.Sized siz t
                       _                       -> A.Sized siz . BitmapIndexed b <$> trim mary 1
                 _ -> do
                     ary2 <- trim mary j
                     return . A.Sized siz $! if j == maxChildren
                                        then Full ary2
                                        else BitmapIndexed b ary2
-            | bi .&. b == 0 = step ary mary b i j (bi `unsafeShiftL` 1) n sz
-            | otherwise = case go sz (A.index ary i) of
+            | bi .&. b == 0 = step ary mary b i j (bi `unsafeShiftL` 1) n siz
+            | otherwise = case go siz (A.index ary i) of
                 A.Sized dsz Empty -> step ary mary (b .&. complement bi) (i+1) j
                                 (bi `unsafeShiftL` 1) n dsz
                 A.Sized dsz t     -> do A.write mary j t
@@ -1334,18 +1334,18 @@ filterMapAuxInternal onLeaf onColl = go 0
         step :: A.Array (Leaf k v1) -> A.MArray s (Leaf k v2)
              -> Int -> Int -> Int -> Int
              -> ST s (A.Sized (Tree k v2))
-        step !ary !mary i !j n !sz
+        step !ary !mary i !j n !sze
             | i >= n    = case j of
-                0 -> return (A.Sized sz Empty)
+                0 -> return (A.Sized sze Empty)
                 1 -> do l <- A.read mary 0
-                        return $! (A.Sized sz (Leaf h l))
+                        return . A.Sized sze $! Leaf h l
                 _ | i == j -> do ary2 <- A.unsafeFreeze mary
-                                 return $! (A.Sized sz (Collision h ary2))
+                                 return . A.Sized sze $! Collision h ary2
                   | otherwise -> do ary2 <- trim mary j
-                                    return $! (A.Sized sz (Collision h ary2))
+                                    return  . A.Sized sze $! Collision h ary2
             | Just el <- onColl (A.index ary i)
-                = A.write mary j el >> step ary mary (i+1) (j+1) n (sz + 1)
-            | otherwise = step ary mary (i+1) j n sz
+                = A.write mary j el >> step ary mary (i+1) (j+1) n (sze + 1)
+            | otherwise = step ary mary (i+1) j n sze
 {-# INLINE filterMapAuxInternal #-}
 
 -- | /O(n)/ Filter this map by retaining only elements which values