Imported Upstream version 6.10.0.49

Former-commit-id: 1d6753294b2993e1fbf92de9366bb9544db4189b

external/llvm-project/compiler-rt/test/tsan/heap_race.cc

@@ -0,0 +1,24 @@
+// RUN: %clangxx_tsan -O1 %s -o %t && %deflake %run %t | FileCheck %s
+#include "test.h"
+#include <pthread.h>
+#include <stdio.h>
+#include <stddef.h>
+
+void *Thread(void *a) {
+  ((int*)a)[0]++;
+  barrier_wait(&barrier);
+  return NULL;
+}
+
+int main() {
+  barrier_init(&barrier, 2);
+  int *p = new int(42);
+  pthread_t t;
+  pthread_create(&t, NULL, Thread, p);
+  barrier_wait(&barrier);
+  p[0]++;
+  pthread_join(t, NULL);
+  delete p;
+}
+
+// CHECK: WARNING: ThreadSanitizer: data race