WIP [esnext] implement async iteration proposal

src/objects-inl.h

Index: src/objects-inl.h
diff --git a/src/objects-inl.h b/src/objects-inl.h
index 5ad593bfa6630d6fe0df69e71a15f6d8efe4a722..e23c1717cf213d7bb14d11c28c397ed0ddad38a6 100644
--- a/src/objects-inl.h
+++ b/src/objects-inl.h
@@ -145,13 +145,14 @@ TYPE_CHECKER(HeapNumber, HEAP_NUMBER_TYPE)
 TYPE_CHECKER(JSArgumentsObject, JS_ARGUMENTS_TYPE)
 TYPE_CHECKER(JSArray, JS_ARRAY_TYPE)
 TYPE_CHECKER(JSArrayBuffer, JS_ARRAY_BUFFER_TYPE)
+TYPE_CHECKER(JSAsyncFromSyncIterator, JS_ASYNC_FROM_SYNC_ITERATOR_TYPE)
+TYPE_CHECKER(JSAsyncGeneratorObject, JS_ASYNC_GENERATOR_OBJECT_TYPE)
 TYPE_CHECKER(JSBoundFunction, JS_BOUND_FUNCTION_TYPE)
 TYPE_CHECKER(JSContextExtensionObject, JS_CONTEXT_EXTENSION_OBJECT_TYPE)
 TYPE_CHECKER(JSDataView, JS_DATA_VIEW_TYPE)
 TYPE_CHECKER(JSDate, JS_DATE_TYPE)
 TYPE_CHECKER(JSError, JS_ERROR_TYPE)
 TYPE_CHECKER(JSFunction, JS_FUNCTION_TYPE)
-TYPE_CHECKER(JSGeneratorObject, JS_GENERATOR_OBJECT_TYPE)
 TYPE_CHECKER(JSGlobalObject, JS_GLOBAL_OBJECT_TYPE)
 TYPE_CHECKER(JSMap, JS_MAP_TYPE)
 TYPE_CHECKER(JSMapIterator, JS_MAP_ITERATOR_TYPE)
@@ -200,6 +201,11 @@ bool HeapObject::IsExternal() const {
   return map() == GetHeap()->external_map();
 }
 
+bool HeapObject::IsJSGeneratorObject() const {
+  return map()->instance_type() == JS_GENERATOR_OBJECT_TYPE ||
+         IsJSAsyncGeneratorObject();
+}
+
 #define SIMD128_TYPE_CHECKER(TYPE, Type, type, lane_count, lane_type) \
   bool HeapObject::Is##Type() const { return map() == GetHeap()->type##_map(); }
 SIMD128_TYPES(SIMD128_TYPE_CHECKER)
@@ -647,11 +653,13 @@ CAST_ACCESSOR(Int8x16)
 CAST_ACCESSOR(JSArray)
 CAST_ACCESSOR(JSArrayBuffer)
 CAST_ACCESSOR(JSArrayBufferView)
+CAST_ACCESSOR(JSAsyncFromSyncIterator)
 CAST_ACCESSOR(JSBoundFunction)
 CAST_ACCESSOR(JSDataView)
 CAST_ACCESSOR(JSDate)
 CAST_ACCESSOR(JSFunction)
 CAST_ACCESSOR(JSGeneratorObject)
+CAST_ACCESSOR(JSAsyncGeneratorObject)
 CAST_ACCESSOR(JSGlobalObject)
 CAST_ACCESSOR(JSGlobalProxy)
 CAST_ACCESSOR(JSMap)
@@ -2169,6 +2177,8 @@ int JSObject::GetHeaderSize(InstanceType type) {
       return JSObject::kHeaderSize;
     case JS_GENERATOR_OBJECT_TYPE:
       return JSGeneratorObject::kSize;
+    case JS_ASYNC_GENERATOR_OBJECT_TYPE:
+      return JSAsyncGeneratorObject::kSize;
     case JS_GLOBAL_PROXY_TYPE:
       return JSGlobalProxy::kSize;
     case JS_GLOBAL_OBJECT_TYPE:
@@ -5770,6 +5780,11 @@ SMI_ACCESSORS(PromiseReactionJobInfo, debug_id, kDebugIdOffset);
 SMI_ACCESSORS(PromiseReactionJobInfo, debug_name, kDebugNameOffset);
 ACCESSORS(PromiseReactionJobInfo, context, Context, kContextOffset);
 
+ACCESSORS(AsyncGeneratorRequest, next, Object, kNextOffset)
+SMI_ACCESSORS(AsyncGeneratorRequest, resume_mode, kResumeModeOffset)
+ACCESSORS(AsyncGeneratorRequest, value, Object, kValueOffset)
+ACCESSORS(AsyncGeneratorRequest, promise, Object, kPromiseOffset)
+
 Map* PrototypeInfo::ObjectCreateMap() {
   return Map::cast(WeakCell::cast(object_create_map())->value());
 }
@@ -6802,6 +6817,11 @@ bool JSGeneratorObject::is_executing() const {
   return continuation() == kGeneratorExecuting;
 }
 
+ACCESSORS(JSAsyncGeneratorObject, queue, HeapObject, kQueueOffset)
+ACCESSORS(JSAsyncGeneratorObject, await_input, Object, kAwaitInputOffset)
+ACCESSORS(JSAsyncGeneratorObject, awaited_promise, HeapObject,
+          kAwaitedPromiseOffset)
+
 ACCESSORS(JSValue, value, Object, kValueOffset)
 
 
@@ -8410,6 +8430,9 @@ ACCESSORS(JSArrayIterator, object_map, Object, kIteratedObjectMapOffset)
 ACCESSORS(JSStringIterator, string, String, kStringOffset)
 SMI_ACCESSORS(JSStringIterator, index, kNextIndexOffset)
 
+ACCESSORS(JSAsyncFromSyncIterator, sync_iterator, HeapObject,
+          kSyncIteratorOffset)
+
 #undef INT_ACCESSORS
 #undef ACCESSORS
 #undef ACCESSORS_CHECKED