tsan: enable clone interceptor only on Linux

Clone does not exist on Mac.
There are chances it will break on other OSes.
Enable it incrementally starting with Linux only,
other OSes can enable it later as needed.

Reviewed By: melver, thakis

Differential Revision: https://reviews.llvm.org/D113693

GitOrigin-RevId: bc84b2857f5bd1550f0be4b0961d6a3ebecfa15d
2 files changed