[destructuring] Re-index materialized literals in arrow function parameters.

src/ast-literal-reindexer.h

+// Copyright 2015 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_LITERAL_REINDEXER
+#define V8_AST_LITERAL_REINDEXER
+
+#include "src/v8.h"
+
+#include "src/ast.h"
+#include "src/scopes.h"
+
+namespace v8 {
+namespace internal {
+
+class AstLiteralReindexer final : public AstVisitor {
+ public:
+  AstLiteralReindexer() : AstVisitor(), next_index_(0) {}
+
+  int count() const { return next_index_; }
+  void Reindex(Expression* pattern);
+
+ private:
+#define DEFINE_VISIT(type) virtual void Visit##type(type* node) override;
+  AST_NODE_LIST(DEFINE_VISIT)
+#undef DEFINE_VISIT
+
+  void VisitStatements(ZoneList<Statement*>* statements) override;
+  void VisitDeclarations(ZoneList<Declaration*>* declarations) override;
+  void VisitArguments(ZoneList<Expression*>* arguments);
+  void VisitObjectLiteralProperty(ObjectLiteralProperty* property);
+
+  void UpdateIndex(MaterializedLiteral* literal) {
+    literal->literal_index_ = next_index_++;
+  }
+
+  void Visit(AstNode* node) override { node->Accept(this); }
+
+  int next_index_;
+
+  DISALLOW_COPY_AND_ASSIGN(AstLiteralReindexer);
+};
+}
+}  // namespace v8::internal
+
+#endif  // V8_AST_LITERAL_REINDEXER