[interpreter] support async functions in Ignition

BUG=v8:4483, v8:4907, 618603
LOG=N
R=neis@chromium.org, yangguo@chromium.org, littledan@chromium.org

Review-Url: https://codereview.chromium.org/2051423003
Cr-Commit-Position: refs/heads/master@{#36938}

src/globals.h

@@ -1024,6 +1024,10 @@ inline bool IsAsyncFunction(FunctionKind kind) {
   return kind & FunctionKind::kAsyncFunction;
 }
 
+inline bool IsResumableFunction(FunctionKind kind) {
+  return IsGeneratorFunction(kind) || IsAsyncFunction(kind);
+}
+
 inline bool IsConciseMethod(FunctionKind kind) {
   DCHECK(IsValidFunctionKind(kind));
   return kind & FunctionKind::kConciseMethod;

src/interpreter/bytecode-generator.cc

@@ -571,7 +571,7 @@ Handle<BytecodeArray> BytecodeGenerator::MakeBytecode() {
 
   RegisterAllocationScope register_scope(this);
 
-  if (IsGeneratorFunction(info()->literal()->kind())) {
+  if (IsResumableFunction(info()->literal()->kind())) {
     generator_state_ = register_allocator()->NewRegister();
     VisitGeneratorPrologue();
   }
@@ -698,8 +698,8 @@ void BytecodeGenerator::VisitGeneratorPrologue() {
 
   builder()->Bind(&regular_call);
   // This is a regular call. Fall through to the ordinary function prologue,
-  // after which we will run into the generator object creation and the initial
-  // yield (both inserted by the parser).
+  // after which we will run into the generator object creation and other extra
+  // code inserted by the parser.
 }
 
 void BytecodeGenerator::VisitBlock(Block* stmt) {

test/mjsunit/harmony/regress/regress-618603.js

+// Copyright 2016 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.
+
+// Flags: --harmony-async-await --ignition-generators
+
+try {
+} catch(e) {; }
+function __f_7(expected, run) {
+  var __v_10 = run();
+};
+__f_7("[1,2,3]", () => (function() {
+      return (async () => {[...await arguments] })();
+      })());