WIP [esnext] implement async iteration proposal

src/compiler/js-typed-lowering.cc

Index: src/compiler/js-typed-lowering.cc
diff --git a/src/compiler/js-typed-lowering.cc b/src/compiler/js-typed-lowering.cc
index ccdf13879ad7d9b6174c481f8cc77a83f80c91fc..c0047f1028bab5f941b68d375a9cc6917da50c98 100644
--- a/src/compiler/js-typed-lowering.cc
+++ b/src/compiler/js-typed-lowering.cc
@@ -2165,19 +2165,21 @@ Reduction JSTypedLowering::ReduceJSGeneratorStore(Node* node) {
   Node* context = NodeProperties::GetContextInput(node);
   Node* effect = NodeProperties::GetEffectInput(node);
   Node* control = NodeProperties::GetControlInput(node);
-  int register_count = OpParameter<int>(node);
+  const GeneratorStoreParameters& p = GeneratorStoreParametersOf(node->op());
 
   FieldAccess array_field = AccessBuilder::ForJSGeneratorObjectRegisterFile();
   FieldAccess context_field = AccessBuilder::ForJSGeneratorObjectContext();
   FieldAccess continuation_field =
       AccessBuilder::ForJSGeneratorObjectContinuation();
   FieldAccess input_or_debug_pos_field =
-      AccessBuilder::ForJSGeneratorObjectInputOrDebugPos();
+      p.suspend_type() == SuspendType::kYield
+          ? AccessBuilder::ForJSGeneratorObjectInputOrDebugPos()
+          : AccessBuilder::ForJSAsyncGeneratorObjectAwaitInput();
 
   Node* array = effect = graph()->NewNode(simplified()->LoadField(array_field),
                                           generator, effect, control);
 
-  for (int i = 0; i < register_count; ++i) {
+  for (int i = 0; i < p.register_count(); ++i) {
     Node* value = NodeProperties::GetValueInput(node, 3 + i);
     effect = graph()->NewNode(
         simplified()->StoreField(AccessBuilder::ForFixedArraySlot(i)), array,