WIP [esnext] implement async iteration proposal

src/parsing/parser.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_PARSING_PARSER_H_
 #define V8_PARSING_PARSER_H_
 
 #include "src/ast/ast.h"
 #include "src/ast/scopes.h"
 #include "src/base/compiler-specific.h"
@@ skipping 440 matching lines @@
                                       int pos);
 
   // Initialize the components of a for-in / for-of statement.
   Statement* InitializeForEachStatement(ForEachStatement* stmt,
                                         Expression* each, Expression* subject,
                                         Statement* body, int each_keyword_pos);
   Statement* InitializeForOfStatement(ForOfStatement* stmt, Expression* each,
                                       Expression* iterable, Statement* body,
                                       bool finalize,
                                       int next_result_pos = kNoSourcePosition);
+  Statement* InitializeForAwaitOfStatement(
+      ForEachStatement* for_of, Expression* each, Expression* iterable,
+      Statement* body, bool finalize, int next_result_pos = kNoSourcePosition);
   Block* RewriteForVarInLegacy(const ForInfo& for_info);
   void DesugarBindingInForEachStatement(ForInfo* for_info, Block** body_block,
                                         Expression** each_variable, bool* ok);
   Block* CreateForEachStatementTDZ(Block* init_block, const ForInfo& for_info,
                                    bool* ok);
 
   Statement* DesugarLexicalBindingsInForStatement(
       ForStatement* loop, Statement* init, Expression* cond, Statement* next,
       Statement* body, Scope* inner_scope, const ForInfo& for_info, bool* ok);
 
@@ skipping 703 matching lines @@
 
  private:
   ParserTarget** variable_;
   ParserTarget* previous_;
 };
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_PARSING_PARSER_H_