Repository: nodejs/node
Pull request: events: getMaxListeners detects 0 listeners

With the removal of the max listeners warning from AbortSignal, a bug was surfaced with getMaxListeners.

```js
> events.getMaxListeners(new AbortController().signal)
Uncaught:
TypeError [ERR_INVALID_ARG_TYPE]: The "emitter" argument must be an instance of EventEmitter or EventTarget. Received an instance of AbortSignal
    at Function.getMaxListeners (node:events:946:9) {
  code: 'ERR_INVALID_ARG_TYPE'
}
```

This causes performance issues for undici.

Refs: https://github.com/nodejs/undici/issues/4032
Refs: https://github.com/nodejs/node/commit/c1ccade02f29fd5585601bd496d4fb615a55b682

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Changed files:
filename: lib/events.js
patch: @@ -939,7 +939,7 @@ function getEventListeners(emitterOrTarget, type) {
 function getMaxListeners(emitterOrTarget) {
   if (typeof emitterOrTarget?.getMaxListeners === 'function') {
     return _getMaxListeners(emitterOrTarget);
-  } else if (emitterOrTarget?.[kMaxEventTargetListeners]) {
+  } else if (typeof emitterOrTarget?.[kMaxEventTargetListeners] === 'number') {
     return emitterOrTarget[kMaxEventTargetListeners];
   }
 

filename: test/parallel/test-events-getmaxlisteners.js
patch: @@ -17,3 +17,8 @@ const { getMaxListeners, EventEmitter, defaultMaxListeners, setMaxListeners } =
   setMaxListeners(101, et);
   assert.strictEqual(getMaxListeners(et), 101);
 }
+
+{
+  const ac = new AbortController();
+  assert.strictEqual(getMaxListeners(ac.signal), 0);
+}