[ASan] Disable invalid-pointer-pairs-threads.cc on Darwin.

pthread barriers are not available on OS X

Differential revision: https://reviews.llvm.org/D40600

llvm-svn: 319681

compiler-rt/test/asan/TestCases/Posix/invalid-pointer-pairs-threads.cc

@@ -3,6 +3,9 @@
 // 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>