[debugger] fix stepping over await calls for ignition generators.

src/runtime/runtime-debug.cc

Index: src/runtime/runtime-debug.cc
diff --git a/src/runtime/runtime-debug.cc b/src/runtime/runtime-debug.cc
index 0142936319c5bf6143592874a8416afa573eb292..945f1236c0ed38bd07a4e5cad4f86342196bbcec 100644
--- a/src/runtime/runtime-debug.cc
+++ b/src/runtime/runtime-debug.cc
@@ -1711,6 +1711,14 @@ RUNTIME_FUNCTION(Runtime_DebugPrepareStepInSuspendedGenerator) {
   return isolate->heap()->undefined_value();
 }
 
+RUNTIME_FUNCTION(Runtime_DebugRecordAsyncFunction) {
+  HandleScope scope(isolate);
+  DCHECK_EQ(1, args.length());
+  CONVERT_ARG_HANDLE_CHECKED(JSGeneratorObject, generator, 0);
+  isolate->debug()->RecordAsyncFunction(generator);
+  return isolate->heap()->undefined_value();
+}
+
 RUNTIME_FUNCTION(Runtime_DebugPushPromise) {
   DCHECK(args.length() == 2);
   HandleScope scope(isolate);