tsan: intercept clone

gtest uses clone for death tests and it needs the same
handling as fork to prevent deadlock (take runtime mutexes
before and release them after).

Reviewed By: melver

Differential Revision: https://reviews.llvm.org/D113677

GitOrigin-RevId: 82de586d4bd7c6a97f5bd30f1eaaa2e326c31612
2 files changed