Merged revisions 285889 via svnmerge from

Merged revisions 285889 via svnmerge from
https://origsvn.digium.com/svn/asterisk/branches/1.4

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  r285889 | tilghman | 2010-09-09 19:13:45 -0500 (Thu, 09 Sep 2010) | 7 lines

  Fix Mac OS X build.

  This also fixes a rather grievous calculation error for the offset of
  ast_fdset, which was masked on Linux and FreeBSD, because these platforms
  check the first 256 FDs regardless of the bitmask setting (due to backwards
  compatibility).
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git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/1.6.2@285930 65c4cc65-6c06-0410-ace0-fbb531ad65f3