py3: do not pass a float to dict_new_presized()

I really don't like the division operator of Python 3 since I'm not doing
a math.

mercurial/dirstate.py

@@ -1431,7 +1431,7 b' class dirstatemap(object):'
             # This heuristic is imperfect in many ways, so in a future dirstate
             # format update it makes sense to just record the number of entries
             # on write.
-            self._map = parsers.dict_new_presized(len(st) / 71)
+            self._map = parsers.dict_new_presized(len(st) // 71)
 
         # Python's garbage collector triggers a GC each time a certain number
         # of container objects (the number being defined by