Debug stub: associate NaClAppThread with IThread

src/trusted/port/thread.h

Index: src/trusted/port/thread.h
diff --git a/src/trusted/port/thread.h b/src/trusted/port/thread.h
index 38664184002b1cbacde41d68d910275dce3a40cb..eed194bb80865c7d78c38cf2e2b160c2cc6f2f05 100644
--- a/src/trusted/port/thread.h
+++ b/src/trusted/port/thread.h
@@ -22,6 +22,8 @@
 
 #include "native_client/src/trusted/port/std_types.h"
 
+struct NaClAppThread;
+
 namespace port {
 
 class IThread {
@@ -50,7 +52,8 @@ class IThread {
 
   virtual void *GetContext() = 0;
 
-  static IThread *Acquire(uint32_t id, bool create = true);
+  static IThread *Create(uint32_t id, struct NaClAppThread *natp);
+  static IThread *Acquire(uint32_t id);
   static void Release(IThread *thread);
   static void SetExceptionCatch(CatchFunc_t func, void *cookie);