Ensure referenced catch block exceptions are in the image.

This addresses Bug: 5732744.

Change-Id: Ia9319b821f94bb27a11358f11b5473bb405277bb
diff --git a/src/object.h b/src/object.h
index 1a58364..ddba9db 100644
--- a/src/object.h
+++ b/src/object.h
@@ -1246,6 +1246,8 @@
 
   bool IsStringClass() const;
 
+  bool IsThrowableClass() const;
+
   Class* GetComponentType() const {
     return GetFieldObject<Class*>(OFFSET_OF_OBJECT_MEMBER(Class, component_type_), false);
   }