[esnext] prototype runtime implementation for async functions

src/d8.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_D8_H_
 #define V8_D8_H_
 
 #ifndef V8_SHARED
 #include "src/allocation.h"
 #include "src/base/platform/time.h"
@@ skipping 383 matching lines @@
   static Local<String> ReadFromStdin(Isolate* isolate);
   static void ReadLine(const v8::FunctionCallbackInfo<v8::Value>& args) {
     args.GetReturnValue().Set(ReadFromStdin(args.GetIsolate()));
   }
   static void Load(const v8::FunctionCallbackInfo<v8::Value>& args);
   static void WorkerNew(const v8::FunctionCallbackInfo<v8::Value>& args);
   static void WorkerPostMessage(
       const v8::FunctionCallbackInfo<v8::Value>& args);
   static void WorkerGetMessage(const v8::FunctionCallbackInfo<v8::Value>& args);
   static void WorkerTerminate(const v8::FunctionCallbackInfo<v8::Value>& args);
+
+  // Run queued microtasks and clear task queue
+  static void FlushMicrotasks(const v8::FunctionCallbackInfo<v8::Value>& args);
+
   // The OS object on the global object contains methods for performing
   // operating system calls:
   //
   // os.system("program_name", ["arg1", "arg2", ...], timeout1, timeout2) will
   // run the command, passing the arguments to the program.  The standard output
   // of the program will be picked up and returned as a multiline string.  If
   // timeout1 is present then it should be a number.  -1 indicates no timeout
   // and a positive number is used as a timeout in milliseconds that limits the
   // time spent waiting between receiving output characters from the program.
   // timeout2, if present, should be a number indicating the limit in
@@ skipping 55 matching lines @@
   static void RunShell(Isolate* isolate);
   static bool SetOptions(int argc, char* argv[]);
   static Local<ObjectTemplate> CreateGlobalTemplate(Isolate* isolate);
 };
 
 
 }  // namespace v8
 
 
 #endif  // V8_D8_H_