[esnext] prototype runtime implementation for async functions

src/isolate.cc

Index: src/isolate.cc
diff --git a/src/isolate.cc b/src/isolate.cc
index 63f670facd02f2338db63406cd6f4aa5e5edeb73..264a29f749779c89d70f0c2c2e6ca4a9169d6ec6 100644
--- a/src/isolate.cc
+++ b/src/isolate.cc
@@ -329,6 +329,7 @@ static bool IsVisibleInStackTrace(JSFunction* fun,
   }
   // Skip all frames until we've seen the caller.
   if (!(*seen_caller)) return false;
+
   // Functions defined in native scripts are not visible unless directly
   // exposed, in which case the native flag is set.
   // The --builtins-in-stack-traces command line flag allows including
@@ -336,6 +337,10 @@ static bool IsVisibleInStackTrace(JSFunction* fun,
   if (!FLAG_builtins_in_stack_traces && fun->shared()->IsBuiltin()) {
     return fun->shared()->native();
   }
+
+  // Async function wrappers are not visible in stack trace
+  if (IsAsyncFunction(fun->shared()->kind())) return false;
+
   return true;
 }