[PATCH] ignore --disable-free in clang when leak detection is enabled

[Sergey Matveev]

  > I'd hate to have to a full clean build with a new -D flag just to change the sense of this one obscure function.

  If you use LSan on top of another tool (which is our main use case) it requires a clean build anyway. In Chromium, for instance, we rely on a compile-time define extensively. But I agree that introducing one just to disable this single flag is not a pretty solution.

http://llvm-reviews.chandlerc.com/D2475