Allow recursive messages reporting as it is already used.

src/isolate.h

Index: src/isolate.h
diff --git a/src/isolate.h b/src/isolate.h
index dd0a1fe51e2fbb319abdf2ea42c8c757327ed086..c29131477c7b317e6faac14ada4f04557e76e2c0 100644
--- a/src/isolate.h
+++ b/src/isolate.h
@@ -188,9 +188,6 @@ class ThreadLocalTop BASE_EMBEDDED {
   // unify them later.
   MaybeObject* scheduled_exception_;
   bool external_caught_exception_;
-  // True if unhandled message is being currently reported by
-  // MessageHandler::ReportMessage.
-  bool in_exception_reporting_;
   SaveContext* save_context_;
   v8::TryCatch* catcher_;
 
@@ -526,12 +523,6 @@ class Isolate {
   bool* external_caught_exception_address() {
     return &thread_local_top_.external_caught_exception_;
   }
-  bool in_exception_reporting() {
-    return thread_local_top_.in_exception_reporting_;
-  }
-  void set_in_exception_reporting(bool value) {
-    thread_local_top_.in_exception_reporting_ = value;
-  }
   v8::TryCatch* catcher() {
     return thread_local_top_.catcher_;
   }