Enter handle scope when creating custom event

Editor assessment

The subject names a very specific internal action, entering a handle scope when creating a custom event, which communicates the mechanism clearly to V8-aware readers while leaving the consequence unstated: was this a leak, a crash, or a correctness issue? The fix type is appropriate, but neither scope nor body supplies the affected area or the defect being repaired. No footers are present, and the style is clean apart from being terse. The message is honest and technically accurate, yet without the diff the reader cannot judge severity or motivation, which limits it to acceptable.