is not needed any more with current versions of FreeBSD.
(Entries 52410 and 52412 in the Bug DB)

That change is based on Dan Nelson replying on the
FreeBSD mailing list, freebsd-questions@freebsd.org
in a thread running from 2010-Apr-29 to 2010-May-1 titled
    "Need info about FreeBSD and interrupted system
     calls for MySQL code"

Also, ensure the cmake settings correspond to the autotools
ones: Add "HAVE_BROKEN_REALPATH" to cmake.

cmake/os/FreeBSD.cmake:
  With current versions of FreeBSD, threading is not done on
  the user-level any more, so the huge "net retry count"
  is not needed any more.
  However, it is still being kept for now, so that it can be
  re-activated should the need arise.
  
  In addition, set "HAVE_BROKEN_REALPATH" to completely
  mirrot the autotools path.
configure.in:
  With current versions of FreeBSD, threading is not done on
  the user-level any more, so the huge "net retry count"
  is not needed any more.
  However, it is still being kept for now, so that it can be
  re-activated should the need arise.
  
  Adapt the informational messages to the path taken.