Additional debug logging for bug 33231647.

Bug: 33231647
Test: m test-art-host
Change-Id: I5847ce92be5f588852e04ff44fe6eca19f363b93
diff --git a/compiler/image_writer.h b/compiler/image_writer.h
index ad6ffd8..c537483 100644
--- a/compiler/image_writer.h
+++ b/compiler/image_writer.h
@@ -50,6 +50,7 @@
 }  // namespace space
 }  // namespace gc
 
+class ClassLoaderVisitor;
 class ClassTable;
 
 static constexpr int kInvalidFd = -1;
@@ -373,6 +374,9 @@
   void ComputeLazyFieldsForImageClasses()
       REQUIRES_SHARED(Locks::mutator_lock_);
 
+  // Visit all class loaders.
+  void VisitClassLoaders(ClassLoaderVisitor* visitor) REQUIRES_SHARED(Locks::mutator_lock_);
+
   // Remove unwanted classes from various roots.
   void PruneNonImageClasses() REQUIRES_SHARED(Locks::mutator_lock_);