Merged revisions 71772 via svnmerge from

Merged revisions 71772 via svnmerge from
svn+ssh://pythondev@svn.python.org/python/trunk

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  r71772 | mark.dickinson | 2009-04-20 22:13:33 +0100 (Mon, 20 Apr 2009) | 5 lines

  Issue #3166: Make long -> float (and int -> float) conversions
  correctly rounded, using round-half-to-even.  This ensures that the
  value of float(n) doesn't depend on whether we're using 15-bit digits
  or 30-bit digits for Python longs.
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