tests/test-dirstate-race.t

parser: use PyInt_FromSsize_t in index_stats

Eliminates

  mercurial/parsers.c(515) : warning C4244: 'function' : conversion from
  'Py_ssize_t' to 'long', possible loss of data
  mercurial/parsers.c(520) : warning C4244: 'function' : conversion from
  'Py_ssize_t' to 'long', possible loss of data
  mercurial/parsers.c(521) : warning C4244: 'function' : conversion from
  'Py_ssize_t' to 'long', possible loss of data

when compiling for Windows x64 target using the Microsoft compiler.

PyInt_FromSsize_t does not exist for Python 2.4 and earlier, so we define a
fallback in util.h to use PyInt_FromLong when compiling for Python 2.4.

  $ hg init
  $ echo a > a
  $ hg add a
  $ hg commit -m test

Do we ever miss a sub-second change?:

  $ for i in 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20; do
  >     hg co -qC 0
  >     echo b > a
  >     hg st
  > done
  M a
  M a
  M a
  M a
  M a
  M a
  M a
  M a
  M a
  M a
  M a
  M a
  M a
  M a
  M a
  M a
  M a
  M a
  M a
  M a