Fix null to integer conversion warnings.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@153395 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Support/Unix/Signals.inc b/lib/Support/Unix/Signals.inc
index 75b91ea..c9ec9fc 100644
--- a/lib/Support/Unix/Signals.inc
+++ b/lib/Support/Unix/Signals.inc
@@ -275,9 +275,9 @@
 
     kern_return_t ret = task_set_exception_ports(self, 
                              mask,
-                             NULL,
+                             MACH_PORT_NULL,
                              EXCEPTION_STATE_IDENTITY | MACH_EXCEPTION_CODES, 
-                             NULL);
+                             THREAD_STATE_NONE);
     (void)ret;
   }
 #endif