Reland: Preprocess structured stack trace on GC to get rid of code reference.

src/objects.h

Index: src/objects.h
diff --git a/src/objects.h b/src/objects.h
index c5b235de4c24cd7f53623efd669ff3893fc9dde0..b80062b8cb270c6aedf765d78c8b980b2d73063c 100644
--- a/src/objects.h
+++ b/src/objects.h
@@ -2632,8 +2632,10 @@ class WeakFixedArray : public FixedArray {
   void Compact();
 
   inline Object* Get(int index) const;
+  inline void Clear(int index);
   inline int Length() const;
 
+  inline bool IsEmptySlot(int index) const;
   static Object* Empty() { return Smi::FromInt(0); }
 
   DECLARE_CAST(WeakFixedArray)
@@ -2648,7 +2650,6 @@ class WeakFixedArray : public FixedArray {
   static void Set(Handle<WeakFixedArray> array, int index,
                   Handle<HeapObject> value);
   inline void clear(int index);
-  inline bool IsEmptySlot(int index) const;
 
   inline int last_used_index() const;
   inline void set_last_used_index(int index);