[libcxx] Add support for sanitizers on OS X.

Summary: This patch adds special configuration logic to find the compiler_rt libraries required by sanitizers on OS X. The supported sanitizers are Address and Undefined.

Reviewers: mclow.lists

Subscribers: cfe-commits

Differential Revision: http://reviews.llvm.org/D11381

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@242858 91177308-0d34-0410-b5e6-96231b3b80d8
3 files changed