[async-iteration] add support for for-await-of loops in Async Functions

src/interpreter/bytecode-array-builder.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_INTERPRETER_BYTECODE_ARRAY_BUILDER_H_
 #define V8_INTERPRETER_BYTECODE_ARRAY_BUILDER_H_
 
 #include "src/ast/ast.h"
 #include "src/base/compiler-specific.h"
 #include "src/globals.h"
@@ skipping 109 matching lines @@
 
   // Named load property.
   BytecodeArrayBuilder& LoadNamedProperty(Register object,
                                           const AstRawString* name,
                                           int feedback_slot);
   // Keyed load property. The key should be in the accumulator.
   BytecodeArrayBuilder& LoadKeyedProperty(Register object, int feedback_slot);
   // Named load property of the @@iterator symbol.
   BytecodeArrayBuilder& LoadIteratorProperty(Register object,
                                              int feedback_slot);
+  // Named load property of the @@asyncIterator symbol.
+  BytecodeArrayBuilder& LoadAsyncIteratorProperty(Register object,
+                                                  int feedback_slot);
 
   // Store properties. Flag for NeedsSetFunctionName() should
   // be in the accumulator.
   BytecodeArrayBuilder& StoreDataPropertyInLiteral(
       Register object, Register name, DataPropertyInLiteralFlags flags,
       int feedback_slot);
 
   // Store a property named by a property name. The value to be stored should be
   // in the accumulator.
   BytecodeArrayBuilder& StoreNamedProperty(Register object,
@@ skipping 334 matching lines @@
   static int const kNoFeedbackSlot = 0;
 
   DISALLOW_COPY_AND_ASSIGN(BytecodeArrayBuilder);
 };
 
 }  // namespace interpreter
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_INTERPRETER_BYTECODE_ARRAY_BUILDER_H_