Merged manually from 2.7 branch to 3.x trunk.

Merged manually from 2.7 branch to 3.x trunk.

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  r80411 | florent.xicluna | 2010-04-23 19:59:10 +0200 (ven. 23 avril 2010) | 2 lignes

  Remove ImportWarnings filters.  They become obsolete after r79310, issue #8205.
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  r80412 | florent.xicluna | 2010-04-23 20:10:12 +0200 (ven. 23 avril 2010) | 2 lignes

  Fix the "regrtest -s" switch.
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  r81140 | florent.xicluna | 2010-05-13 19:05:29 +0200 (jeu. 13 mai 2010) | 3 lignes

  Add sensible information about the OS X platform to diagnose issue #8423:
  test_pep277 fails on "x86 Tiger" buildbot but not on "PPC Tiger".
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  r81141 | florent.xicluna | 2010-05-13 20:16:06 +0200 (jeu. 13 mai 2010) | 2 lignes

  Revert the additional OS X information (r81140).  Keep the endianness information.
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