[PATCH] A couple minor changes to support sanitizers on FreeBSD 9.2

[Alexey Samsonov]

  What error do you observe if _SIZE_T_DECLARED is not defined? How does other programs on FreeBSD work around these issue? I'm not convinced that introducing a hack to the build
  system is appropriate here. It will also unlikely be the only place where we use it - e.g. would you need the same for building sanitizer_common unit tests (run by check-sanitizer command)?

http://llvm-reviews.chandlerc.com/D3031