Unblocked and merged revisions 67611 via svnmerge from

Unblocked and merged revisions 67611 via svnmerge from
svn+ssh://pythondev@svn.python.org/python/branches/py3k

................
  r67611 | jeffrey.yasskin | 2008-12-06 09:09:27 -0800 (Sat, 06 Dec 2008) | 11 lines

  Merged revisions 67494 via svnmerge from
  svn+ssh://pythondev@svn.python.org/python/trunk

  ........
    r67494 | jeffrey.yasskin | 2008-12-02 22:46:45 -0800 (Tue, 02 Dec 2008) | 5 lines

    Speed up Python (according to pybench and 2to3-on-itself) by 1-2% by caching
    whether any thread has tracing turned on, which saves one load instruction in
    the fast_next_opcode path in PyEval_EvalFrameEx().  See issue 4477.
  ........
................