[PATCH] Moar string interceptors: strstr, strcasestr, strcspn, strpbrk

[Yury Gribov]

> The interceptors should enforce the contract.

I believe sanitizer folks are in unfortunate situation where they have to deal with tons of legacy crap which relies heavily on glibc quirks (there's a lot of code like this, some in binary form with no ability to recompile). So I can feel their pain. On the other hand we shouldn't force users which deal with saner codebases (me or Joerg) to use overly conservative tool.

http://reviews.llvm.org/D6056