WIP [esnext] implement async iteration proposal

src/compiler/js-intrinsic-lowering.h

Index: src/compiler/js-intrinsic-lowering.h
diff --git a/src/compiler/js-intrinsic-lowering.h b/src/compiler/js-intrinsic-lowering.h
index 05ae3256a4ed82f38f03daeaa3ad42231426f379..960c1e457eac000125f7085054e57102d900773a 100644
--- a/src/compiler/js-intrinsic-lowering.h
+++ b/src/compiler/js-intrinsic-lowering.h
@@ -44,6 +44,8 @@ class V8_EXPORT_PRIVATE JSIntrinsicLowering final
   Reduction ReduceDeoptimizeNow(Node* node);
   Reduction ReduceGeneratorClose(Node* node);
   Reduction ReduceGeneratorGetInputOrDebugPos(Node* node);
+  Reduction ReduceGeneratorGetAwaitInput(Node* node);
+  Reduction ReduceGeneratorSaveInputForAwait(Node* node);
   Reduction ReduceGeneratorGetResumeMode(Node* node);
   Reduction ReduceIsInstanceType(Node* node, InstanceType instance_type);
   Reduction ReduceIsJSReceiver(Node* node);