improvements to code that checks whether Python (obmalloc) allocated an address

- Rename Py_ADDRESS_IN_RANGE to address_in_range and make it a static
  function instead of macro. Any compiler worth its salt will inline this
  function.
- Remove the duplicated function version of Py_ADDRESS_IN_RANGE used when memory
  analysis was active. Instead, we can simply mark address_in_range as allergic
  to dynamic memory checking. We can now remove the
  __attribute__((no_address_safety_analysis)) from _PyObject_Free and
  _PyObject_Realloc. All the badness is contained in address_in_range now.
- Fix the code that tried to only read pool->arenaindex once. Putting something
  in a variable is no guarantee that it won't be read multiple times. We must
  use volatile for that.