WIP [esnext] implement async iteration proposal

src/compiler/access-builder.h

 // Copyright 2014 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_COMPILER_ACCESS_BUILDER_H_
 #define V8_COMPILER_ACCESS_BUILDER_H_
 
 #include "src/base/compiler-specific.h"
 #include "src/compiler/simplified-operator.h"
 #include "src/elements-kind.h"
@@ skipping 56 matching lines @@
 
   // Provides access to JSGeneratorObject::context() field.
   static FieldAccess ForJSGeneratorObjectContext();
 
   // Provides access to JSGeneratorObject::continuation() field.
   static FieldAccess ForJSGeneratorObjectContinuation();
 
   // Provides access to JSGeneratorObject::input_or_debug_pos() field.
   static FieldAccess ForJSGeneratorObjectInputOrDebugPos();
 
+  // Provides access to JSAsyncGeneratorObject::await_input() field.
+  static FieldAccess ForJSAsyncGeneratorObjectAwaitInput();
+
   // Provides access to JSGeneratorObject::register_file() field.
   static FieldAccess ForJSGeneratorObjectRegisterFile();
 
   // Provides access to JSGeneratorObject::resume_mode() field.
   static FieldAccess ForJSGeneratorObjectResumeMode();
 
   // Provides access to JSArray::length() field.
   static FieldAccess ForJSArrayLength(ElementsKind elements_kind);
 
   // Provides access to JSArrayBuffer::backing_store() field.
@@ skipping 159 matching lines @@
 
  private:
   DISALLOW_IMPLICIT_CONSTRUCTORS(AccessBuilder);
 };
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_COMPILER_ACCESS_BUILDER_H_