Merged revisions 68889 via svnmerge from

Merged revisions 68889 via svnmerge from
svn+ssh://pythondev@svn.python.org/python/branches/py3k

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  r68889 | mark.dickinson | 2009-01-24 15:02:35 +0000 (Sat, 24 Jan 2009) | 9 lines

  Some minor cleanups in PyLong_FromLong:
   - fast path wasn't being properly taken for negative ints;
     thanks Victor Stinner for pointing this out.
   - use Py_SAFE_DOWNCAST instead of direct casting to digit
     (it's safer, especially if we ever consider moving to 30-bit
     digits)
   - cleaner way to write negation
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