Work in progress: allow pause-on-exceptions to work in Object.observe callbacks

src/debug.cc

Index: src/debug.cc
diff --git a/src/debug.cc b/src/debug.cc
index 4a58766e53d340c551e1d8925437e5367b212ffe..b1193582eb91cee899ffc9eb776a126dee08c03a 100644
--- a/src/debug.cc
+++ b/src/debug.cc
@@ -2558,6 +2558,8 @@ void Debug::OnException(Handle<Object> exception, bool uncaught,
         isolate_, has_reject_handler,
         PromiseHasUserDefinedRejectHandler(jspromise), /* void */);
     uncaught = has_reject_handler->IsFalse();
+  } else if (!uncaught && promise->IsNull()) {
+    uncaught = true;
   }
   // Bail out if exception breaks are not active
   if (uncaught) {