[Tsan] Fix the atomic_race.cc test to pass on systems with high loads

[kutuzov.viktor.84]

Summary

The current delay duration is too short for the FreeBSD buildbot slave:

http://lab.llvm.org:8011/buildslaves/as-bldslv5

that serves several FreeBSD buildbots:

http://lab.llvm.org:8011/builders/sanitizer_x86_64-freebsd
http://lab.llvm.org:8011/builders/lld-x86_64-freebsd
http://lab.llvm.org:8011/builders/clang-mergefunc-x86_64-freebsd

and runs the lit tests in 64 threads (which is what lit.py does by default on this machine). Due to this insufficient delay the output for the reverse tests come before the output for the ordinary ones. It seems with four-second delay we pass this test persistently.

[dvyukov]

LGTM

Closed by commit rL223122 (authored by vkutuzov).

test/tsan/atomic_race.cc

else
       sink = *p;
   }
 }
 
 void *Thread(void *p) {
   for (int i = 0; i < kTestCount; i++) {
     Test(i, &atomics[i], false);
   }
-  sleep(2);
+  sleep(4);
   for (int i = 0; i < kTestCount; i++) {
     fprintf(stderr, "Test %d reverse\n", i);
     Test(i, &atomics[kTestCount + i], false);
   }
   return 0;
 }
 
 int main() {