[esnext] prototype runtime implementation for async functions

src/globals.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_GLOBALS_H_
 #define V8_GLOBALS_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
@@ skipping 952 matching lines @@
   kBaseConstructor = 1 << 5,
   kGetterFunction = 1 << 6,
   kSetterFunction = 1 << 7,
   kAsyncFunction = 1 << 8,
   kAccessorFunction = kGetterFunction | kSetterFunction,
   kDefaultBaseConstructor = kDefaultConstructor | kBaseConstructor,
   kDefaultSubclassConstructor = kDefaultConstructor | kSubclassConstructor,
   kClassConstructor =
       kBaseConstructor | kSubclassConstructor | kDefaultConstructor,
   kAsyncArrowFunction = kArrowFunction | kAsyncFunction,
-  kAsyncConciseMethod = kAsyncFunction | kConciseMethod
+  kAsyncConciseMethod = kAsyncFunction | kConciseMethod,
+  kArrowGeneratorFunction = kGeneratorFunction | kArrowFunction
 };
 
 inline bool IsValidFunctionKind(FunctionKind kind) {
   return kind == FunctionKind::kNormalFunction ||
          kind == FunctionKind::kArrowFunction ||
          kind == FunctionKind::kGeneratorFunction ||
          kind == FunctionKind::kConciseMethod ||
          kind == FunctionKind::kConciseGeneratorMethod ||
          kind == FunctionKind::kGetterFunction ||
          kind == FunctionKind::kSetterFunction ||
          kind == FunctionKind::kAccessorFunction ||
          kind == FunctionKind::kDefaultBaseConstructor ||
          kind == FunctionKind::kDefaultSubclassConstructor ||
          kind == FunctionKind::kBaseConstructor ||
          kind == FunctionKind::kSubclassConstructor ||
          kind == FunctionKind::kAsyncFunction ||
          kind == FunctionKind::kAsyncArrowFunction ||
-         kind == FunctionKind::kAsyncConciseMethod;
+         kind == FunctionKind::kAsyncConciseMethod ||
+         kind == FunctionKind::kArrowGeneratorFunction;
 }
 
 
 inline bool IsArrowFunction(FunctionKind kind) {
   DCHECK(IsValidFunctionKind(kind));
   return kind & FunctionKind::kArrowFunction;
 }
 
 
 inline bool IsGeneratorFunction(FunctionKind kind) {
@@ skipping 49 matching lines @@
   DCHECK(IsValidFunctionKind(kind));
   return kind & FunctionKind::kClassConstructor;
 }
 
 
 inline bool IsConstructable(FunctionKind kind, LanguageMode mode) {
   if (IsAccessorFunction(kind)) return false;
   if (IsConciseMethod(kind)) return false;
   if (IsArrowFunction(kind)) return false;
   if (IsGeneratorFunction(kind)) return false;
+  if (IsAsyncFunction(kind)) return false;
   return true;
 }
 
 
 inline uint32_t ObjectHash(Address address) {
   // All objects are at least pointer aligned, so we can remove the trailing
   // zeros.
   return static_cast<uint32_t>(bit_cast<uintptr_t>(address) >>
                                kPointerSizeLog2);
 }
 
+enum class AsyncFunctionResumeMode {
+  Normal,
+  Throw,
+};
+
 }  // namespace internal
 }  // namespace v8
 
 namespace i = v8::internal;
 
 #endif  // V8_GLOBALS_H_