Static global object don't work well, if the variables are

accessed during the construction of another static global
object because there are no guarantees on ordering of
construction, so stick the static global into a function
as a static local and return a reference to the variable.
This fixes the exit callback stuff on my Mac.

--HG--
extra : convert_revision : 63a3844d0b5ee18e2011f1bc7ca7bb703284da94

src/sim/main.cc

@@ -414,7 +414,12 @@ unserializeAll(const std::string &cpt_dir)
 /**
  * Queue of C++ callbacks to invoke on simulator exit.
  */
-CallbackQueue exitCallbacks;
+CallbackQueue&
+exitCallbacks()
+{
+    static CallbackQueue theQueue;
+    return theQueue;
+}
 
 /**
  * Register an exit callback.
@@ -422,7 +427,7 @@ CallbackQueue exitCallbacks;
 void
 registerExitCallback(Callback *callback)
 {
-    exitCallbacks.add(callback);
+    exitCallbacks().add(callback);
 }
 
 BaseCPU *
@@ -442,8 +447,8 @@ convertToBaseCPUPtr(SimObject *obj)
 void
 doExitCleanup()
 {
-    exitCallbacks.process();
-    exitCallbacks.clear();
+    exitCallbacks().process();
+    exitCallbacks().clear();
 
     cout.flush();