Async/await catch prediction for "the synchronous case"

src/isolate.h

Index: src/isolate.h
diff --git a/src/isolate.h b/src/isolate.h
index a00831239604195004dc999d192b166f8546bdb3..9a2363fa3938f79075fd021b44077df2473f31fa 100644
--- a/src/isolate.h
+++ b/src/isolate.h
@@ -675,6 +675,9 @@ class Isolate {
   void PopPromise();
   Handle<Object> GetPromiseOnStackOnThrow();
 
+  // Heuristically guess whether a Promise is handled by user catch handler
+  bool PromiseHasUserDefinedRejectHandler(Handle<Object> promise);
+
   class ExceptionScope {
    public:
     // Scope currently can only be used for regular exceptions,