For Stack Indirect Reference Table, visit roots in the table.

Change-Id: Ib2574c54b080944e0be3c498578520d52df4d9ec
diff --git a/src/thread.h b/src/thread.h
index db5bbe8..3a8abba 100644
--- a/src/thread.h
+++ b/src/thread.h
@@ -392,6 +392,8 @@
   // Is the given obj in this thread's stack indirect reference table?
   bool SirtContains(jobject obj);
 
+  void SirtVisitRoots(Heap::RootVisitor* visitor, void* arg);
+
   // Pop the top SIRT
   void PopSirt();