Resurrection of "Hooks for out-of-process (OOP) debugger" CL.

src/trusted/service_runtime/osx/nacl_oop_debugger_hooks.c

+/*
+ * Copyright (c) 2011 The Native Client Authors. All rights reserved.
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include "native_client/src/include/nacl_platform.h"
+#include "native_client/src/trusted/service_runtime/nacl_oop_debugger_hooks.h"
+
+/* placeholders */
+void NaClOopDebuggerAppCreateHook(struct NaClApp *nap) {
+  UNREFERENCED_PARAMETER(nap);
+}
+
+void NaClOopDebuggerThreadCreateHook(struct NaClAppThread *natp) {
+  UNREFERENCED_PARAMETER(natp);
+}
+void NaClOopDebuggerThreadExitHook(struct NaClAppThread *natp,
+                                   int exit_code) {
+  UNREFERENCED_PARAMETER(natp);
+  UNREFERENCED_PARAMETER(exit_code);
+}
+
+void NaClOopDebuggerAppExitHook(int exit_code) {
+  UNREFERENCED_PARAMETER(exit_code);
+}
+