Backporting since it would have helped us find a regression.

Merged revisions 75314 via svnmerge from
svn+ssh://pythondev@svn.python.org/python/branches/py3k

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  r75314 | antoine.pitrou | 2009-10-10 23:08:31 +0200 (sam., 10 oct. 2009) | 10 lines

  Merged revisions 75312 via svnmerge from
  svn+ssh://pythondev@svn.python.org/python/trunk

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    r75312 | antoine.pitrou | 2009-10-10 22:52:11 +0200 (sam., 10 oct. 2009) | 4 lines

    Issue #7055: test___all__ now greedily detects all modules which have an
    __all__ attribute, rather than using a hardcoded and incomplete list.
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