8269594: assert(_handle_mark_nesting > 1) failed: memory leak: allocating handle outside HandleMark

Reviewed-by: coleenp, jvernee

src/hotspot/share/runtime/safepoint.cpp

@@ -928,6 +928,7 @@ void ThreadSafepointState::handle_polling_page_exception() {
   if( nm->is_at_poll_return(real_return_addr) ) {
     // See if return type is an oop.
     bool return_oop = nm->method()->is_returning_oop();
+    HandleMark hm(self);
     Handle return_value;
     if (return_oop) {
       // The oop result has been saved on the stack together with all