Do not use js builtins object to determine whether a function is a builtin.

src/debug/debug.cc

Index: src/debug/debug.cc
diff --git a/src/debug/debug.cc b/src/debug/debug.cc
index 2bda0a7137a12323e2f112be99bc07b4d452fb29..c98bd5748cc9037add997dd9017a7f583088793b 100644
--- a/src/debug/debug.cc
+++ b/src/debug/debug.cc
@@ -2277,7 +2277,7 @@ void Debug::HandleDebugBreak() {
     Object* fun = it.frame()->function();
     if (fun && fun->IsJSFunction()) {
       // Don't stop in builtin functions.
-      if (JSFunction::cast(fun)->IsBuiltin()) return;
+      if (!JSFunction::cast(fun)->IsSubjectToDebugging()) return;
       GlobalObject* global = JSFunction::cast(fun)->context()->global_object();
       // Don't stop in debugger functions.
       if (IsDebugGlobal(global)) return;