Refactor AOT deduplication steps so they can run before an app-jit snapshot as well.

runtime/vm/program_visitor.h

Index: runtime/vm/program_visitor.h
diff --git a/runtime/vm/program_visitor.h b/runtime/vm/program_visitor.h
index 5ac81308622799902692944f32bed8a640e0f925..cdc6b0191de53275e85e11ce4b8da3a23d75e52e 100644
--- a/runtime/vm/program_visitor.h
+++ b/runtime/vm/program_visitor.h
@@ -26,6 +26,17 @@ class ProgramVisitor : public AllStatic {
  public:
   static void VisitFunctions(FunctionVisitor* visitor);
   static void VisitClasses(ClassVisitor* visitor);
+
+  static void Dedup();
+
+ private:
+  static void ShareMegamorphicBuckets();
+  static void DedupStackMaps();
+  static void DedupPcDescriptors();
+  static void DedupDeoptEntries();
+  static void DedupCodeSourceMaps();
+  static void DedupLists();
+  static void DedupInstructions();
 };
 
 }  // namespace dart