[PATCH] Optional support for dynamic Asan runtime

[Yury Gribov]

  I think I found a reasonably robust way to detect that dynamic rt was either linked to exectable or preloaded (and thus can be used safely). I can simply check that it preceedes other dynamic libraries in list returned by dl_iterate_phdr. This would also prohibit dlopens.

  Still not sure how to detect static/shared rt conflicts though.

http://llvm-reviews.chandlerc.com/D3042