[TSan] Support fiber API on macOS

Committing on behalf of Yuri Per (yuri).

Reviewers: dvyukov, kubamracek, yln

Reviewed By: kubamracek

Authored By: yuri

Differential Revision: https://reviews.llvm.org/D58110

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@358802 91177308-0d34-0410-b5e6-96231b3b80d8
15 files changed