https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78158
--- Comment #8 from Dmitry Vyukov <dvyukov at google dot com> --- We need to modify tsan runtime to ignore (zero) __ATOMIC_HLE_ACQUIRE/RELEASE bits, right? It's only an optimization and we can pretend that elision never succeeds under tsan. What is sync special bit (0x4000)?
