[inspector] introduced stepIntoAsync for chained callbacks

src/runtime/runtime-debug.cc

 // Copyright 2014 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/runtime/runtime-utils.h"
 
 #include "src/arguments.h"
 #include "src/compiler.h"
 #include "src/debug/debug-coverage.h"
 #include "src/debug/debug-evaluate.h"
@@ skipping 1951 matching lines @@
   return *factory->NewJSArrayWithElements(scripts_array, FAST_ELEMENTS);
 }
 
 RUNTIME_FUNCTION(Runtime_DebugTogglePreciseCoverage) {
   SealHandleScope shs(isolate);
   CONVERT_BOOLEAN_ARG_CHECKED(enable, 0);
   Coverage::TogglePrecise(isolate, enable);
   return isolate->heap()->undefined_value();
 }
 
+RUNTIME_FUNCTION(Runtime_DebugMarkAsPromiseBuiltin) {
+  HandleScope scope(isolate);
+  DCHECK_EQ(1, args.length());
+  CONVERT_ARG_HANDLE_CHECKED(JSFunction, fun, 0);
+  fun->shared()->set_is_promise_builtin(true);
+  return isolate->heap()->undefined_value();
+}
+
 }  // namespace internal
 }  // namespace v8