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..04d0a6754ec6cec98025d49c23dd51a6312ce9f1 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 ReduceAsyncGeneratorGetAwaitInput(Node* node);
+  Reduction ReduceGeneratorSaveInputForAwait(Node* node);
   Reduction ReduceGeneratorGetResumeMode(Node* node);
   Reduction ReduceIsInstanceType(Node* node, InstanceType instance_type);
   Reduction ReduceIsJSReceiver(Node* node);