Turn the unresolved-references list into a linked list using the VariableProxies themselves

src/ast/ast.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_AST_AST_H_
 #define V8_AST_AST_H_
 
 #include "src/ast/ast-value-factory.h"
 #include "src/ast/modules.h"
 #include "src/ast/variables.h"
@@ skipping 1647 matching lines @@
     return var()->IsUnallocated() || var()->IsLookupSlot();
   }
 
   void AssignFeedbackVectorSlots(Isolate* isolate, FeedbackVectorSpec* spec,
                                  FeedbackVectorSlotCache* cache);
 
   FeedbackVectorSlot VariableFeedbackSlot() { return variable_feedback_slot_; }
 
   static int num_ids() { return parent_num_ids() + 1; }
   BailoutId BeforeId() const { return BailoutId(local_id(0)); }
+  void set_next_unresolved(VariableProxy* next) { next_unresolved_ = next; }
+  VariableProxy* next_unresolved() { return next_unresolved_; }
 
  protected:
   VariableProxy(Zone* zone, Variable* var, int start_position,
                 int end_position);
 
   VariableProxy(Zone* zone, const AstRawString* name,
                 Variable::Kind variable_kind, int start_position,
                 int end_position);
   static int parent_num_ids() { return Expression::num_ids(); }
   int local_id(int n) const { return base_id() + parent_num_ids() + n; }
 
   class IsThisField : public BitField8<bool, 0, 1> {};
   class IsAssignedField : public BitField8<bool, 1, 1> {};
   class IsResolvedField : public BitField8<bool, 2, 1> {};
   class IsNewTargetField : public BitField8<bool, 3, 1> {};
 
   // Start with 16-bit (or smaller) field, which should get packed together
   // with Expression's trailing 16-bit field.
   uint8_t bit_field_;
   // Position is stored in the AstNode superclass, but VariableProxy needs to
   // know its end position too (for error messages). It cannot be inferred from
   // the variable name length because it can contain escapes.
   int end_position_;
   FeedbackVectorSlot variable_feedback_slot_;
   union {
     const AstRawString* raw_name_;  // if !is_resolved_
     Variable* var_;                 // if is_resolved_
   };
+  VariableProxy* next_unresolved_;
 };
 
 
 // Left-hand side can only be a property, a global or a (parameter or local)
 // slot.
 enum LhsKind {
   VARIABLE,
   NAMED_PROPERTY,
   KEYED_PROPERTY,
   NAMED_SUPER_PROPERTY,
@@ skipping 1834 matching lines @@
                                     : NULL;                                   \
   }
 AST_NODE_LIST(DECLARE_NODE_FUNCTIONS)
 #undef DECLARE_NODE_FUNCTIONS
 
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_AST_AST_H_