[destructuring] Adapting PatternRewriter to work in for-statements.

src/pattern-rewriter.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_PATTERN_MATCHER_H_
-#define V8_PATTERN_MATCHER_H_
-
-#include "src/ast.h"
-#include "src/parser.h"
-
-namespace v8 {
-
-namespace internal {
-
-class Parser::PatternRewriter : private AstVisitor {
- public:
-  struct DeclarationDescriptor {
-    Parser* parser;
-    Scope* declaration_scope;
-    Scope* scope;
-    int initializer_position;
-    VariableMode mode;
-    ZoneList<const AstRawString*>* names;
-    bool is_const;
-    Block* block;
-    bool needs_init;
-    int pos;
-    Token::Value init_op;
-  };
-
-  explicit PatternRewriter(const DeclarationDescriptor* decl,
-                           Expression* pattern)
-      : decl_(decl),
-        pattern_(pattern),
-        current_value_(nullptr),
-        ok_(nullptr),
-        nvars_(nullptr) {}
-
-  PatternRewriter()
-      : decl_(nullptr),
-        pattern_(nullptr),
-        current_value_(nullptr),
-        ok_(nullptr),
-        nvars_(nullptr) {}
-
-  bool IsSingleVariableBinding() const;
-  const AstRawString* SingleName() const;
-
-  void DeclareAndInitializeVariables(Expression* value, int* nvars, bool* ok);
-
- private:
-#define DECLARE_VISIT(type) void Visit##type(v8::internal::type* node) override;
-  // Visiting functions for AST nodes make this an AstVisitor.
-  AST_NODE_LIST(DECLARE_VISIT)
-#undef DECLARE_VISIT
-  virtual void Visit(AstNode* node) override;
-
-  void RecurseIntoSubpattern(AstNode* pattern, Expression* value) {
-    Expression* old_value = current_value_;
-    current_value_ = value;
-    pattern->Accept(this);
-    current_value_ = old_value;
-  }
-
-  AstNodeFactory* factory() const { return decl_->parser->factory(); }
-  AstValueFactory* ast_value_factory() const {
-    return decl_->parser->ast_value_factory();
-  }
-  bool inside_with() const { return decl_->parser->inside_with(); }
-  Zone* zone() const { return decl_->parser->zone(); }
-
-  const DeclarationDescriptor* decl_;
-  Expression* pattern_;
-  Expression* current_value_;
-  bool* ok_;
-  int* nvars_;
-};
-}
-}  // namespace v8::internal
-
-
-#endif  // V8_PATTERN_MATCHER_H_