WIP [esnext] implement async iteration proposal

src/code-factory.cc

Index: src/code-factory.cc
diff --git a/src/code-factory.cc b/src/code-factory.cc
index ab652964c65fdf5c43422c760318529aa075b53d..eeb62e2b4bb4e87af6f988cf38d7238b55e0fd40 100644
--- a/src/code-factory.cc
+++ b/src/code-factory.cc
@@ -350,6 +350,12 @@ Callable CodeFactory::ResumeGenerator(Isolate* isolate) {
 }
 
 // static
+Callable CodeFactory::ResumeAwaitedGenerator(Isolate* isolate) {
+  return Callable(isolate->builtins()->ResumeAwaitedGeneratorTrampoline(),
+                  ResumeGeneratorDescriptor(isolate));
+}
+
+// static
 Callable CodeFactory::FastCloneRegExp(Isolate* isolate) {
   return Callable(isolate->builtins()->FastCloneRegExp(),
                   FastCloneRegExpDescriptor(isolate));