runtime: indirect subclass of a native base inherits nothing (`class D extends B`, `class B extends EventEmitter`)

[proggeramlug]

Summary

An indirect subclass of a native base inherits nothing. The base's method surface is only installed when the class literally names the base in its extends clause, so one level of indirection loses it entirely.

Confirmed on clean origin/main.

Repro

import { EventEmitter } from "node:events";
class B extends EventEmitter {}
class D extends B {}          // one hop away from the native base
const d = new D();
console.log("typeof d.on:", typeof d.on, "typeof d.emit:", typeof d.emit);

	output
node 26	typeof d.on: function typeof d.emit: function
perry main	typeof d.on: undefined typeof d.emit: undefined

new D() is a usable EventEmitter in Node; in perry it has no emitter surface at all. No override is involved — plain two-level inheritance.

Root cause

js_event_emitter_subclass_init only fires when extends_name is literally EventEmitter. A class whose parent is itself an EventEmitter subclass never runs the init, so the method surface is never installed.

Fix direction

This is the EventEmitter mirror of the class-chain walk that PR #6311 added for EventTarget (which reserved CLASS_ID_EVENT_TARGET and wired the registry parent edge so inheritance resolves at any depth). The init needs to trigger on "the class chain reaches EventEmitter", not on a literal extends name match.

Surfaced while fixing #6316 (PR #6322), which deliberately documents this exclusion in its fixture rather than silently passing it. Two-level subclassing of EventEmitter is a very common Node pattern.