[Bug sanitizer/78158] Strange data race detection with thread sanitizer

[dvyukov at google dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78158

--- Comment #18 from Dmitry Vyukov <dvyukov at google dot com> ---
Landed http://llvm.org/viewvc/llvm-project?view=revision&revision=298378 with
0x7fff mask.