tsan: disable signal_sync2.cpp test on powerpc64
Fails 1 out of 10 runs on powerpc bots:
https://lab.llvm.org/buildbot/#/builders/121/builds/13391
Reviewed By: nemanjai
Differential Revision: https://reviews.llvm.org/D114426
GitOrigin-RevId: d75ed9864acb15d1543e839fe4627c9b1d867c22
diff --git a/test/tsan/signal_sync2.cpp b/test/tsan/signal_sync2.cpp
index 7d00296..a1c31dc 100644
--- a/test/tsan/signal_sync2.cpp
+++ b/test/tsan/signal_sync2.cpp
@@ -1,5 +1,8 @@
// RUN: %clangxx_tsan -O1 %s -o %t && %run %t 2>&1 | FileCheck %s
// UNSUPPORTED: darwin
+// Fails episodically on powerpc bots:
+// https://lab.llvm.org/buildbot/#/builders/121/builds/13391
+// UNSUPPORTED: powerpc64, powerpc64le
#include "test.h"
#include <errno.h>
#include <signal.h>