[ASan] Disable invalid-pointer-pairs-threads.cc on Darwin.
pthread barriers are not available on OS X
// RUN: %env_asan_opts=detect_invalid_pointer_pairs=1 %run %t a 2>&1 | FileCheck %s -check-prefix=OK -allow-empty
// RUN: %env_asan_opts=detect_invalid_pointer_pairs=1 not %run %t b 2>&1 | FileCheck %s -check-prefix=B
+// pthread barriers are not available on OS X
+// UNSUPPORTED: darwin
+
#include <assert.h>
#include <pthread.h>
#include <stdlib.h>
