WIP [esnext] implement async iteration proposal

src/objects-printer.cc

 // 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.
 
 #include "src/objects.h"
 
 #include <iomanip>
 #include <memory>
 
 #include "src/bootstrapper.h"
@@ skipping 132 matching lines @@
       break;
 
     case FILLER_TYPE:
       os << "filler";
       break;
     case JS_OBJECT_TYPE:  // fall through
     case JS_API_OBJECT_TYPE:
     case JS_SPECIAL_API_OBJECT_TYPE:
     case JS_CONTEXT_EXTENSION_OBJECT_TYPE:
     case JS_GENERATOR_OBJECT_TYPE:
+    case JS_ASYNC_GENERATOR_OBJECT_TYPE:
     case JS_ARGUMENTS_TYPE:
     case JS_ERROR_TYPE:
     case JS_PROMISE_CAPABILITY_TYPE:
       JSObject::cast(this)->JSObjectPrint(os);
       break;
     case JS_PROMISE_TYPE:
       JSPromise::cast(this)->JSPromisePrint(os);
       break;
     case JS_ARRAY_TYPE:
       JSArray::cast(this)->JSArrayPrint(os);
@@ skipping 1094 matching lines @@
   os << "\n - tasks: " << Brief(tasks());
   os << "\n - deferred_promise: " << Brief(deferred_promise());
   os << "\n - deferred_on_resolve: " << Brief(deferred_on_resolve());
   os << "\n - deferred_on_reject: " << Brief(deferred_on_reject());
   os << "\n - debug id: " << debug_id();
   os << "\n - debug name: " << debug_name();
   os << "\n - reaction context: " << Brief(context());
   os << "\n";
 }
 
+void AsyncGeneratorRequest::AsyncGeneratorRequestPrint(
+    std::ostream& os) {  // NOLINT
+  HeapObject::PrintHeader(os, "AsyncGeneratorRequest");
+  const char* mode = "Invalid!";
+  switch (resume_mode()) {
+    case JSGeneratorObject::kNext:
+      mode = ".next()";
+      break;
+    case JSGeneratorObject::kReturn:
+      mode = ".return()";
+      break;
+    case JSGeneratorObject::kThrow:
+      mode = ".throw()";
+      break;
+  }
+  os << "\n - resume mode: " << mode;
+  os << "\n - value: " << Brief(value());
+  os << "\n";
+}
+
 void ModuleInfoEntry::ModuleInfoEntryPrint(std::ostream& os) {  // NOLINT
   HeapObject::PrintHeader(os, "ModuleInfoEntry");
   os << "\n - export_name: " << Brief(export_name());
   os << "\n - local_name: " << Brief(local_name());
   os << "\n - import_name: " << Brief(import_name());
   os << "\n - module_request: " << module_request();
   os << "\n - cell_index: " << cell_index();
   os << "\n - beg_pos: " << beg_pos();
   os << "\n - end_pos: " << end_pos();
   os << "\n";
@@ skipping 427 matching lines @@
     printf("Not a transition array\n");
   } else {
     reinterpret_cast<i::TransitionArray*>(object)->Print();
   }
 }
 
 extern void _v8_internal_Print_StackTrace() {
   i::Isolate* isolate = i::Isolate::Current();
   isolate->PrintStack(stdout);
 }