Fix EventEmitter prototype-key event types (#58229)

Summary:
The shared EventEmitter uses an ordinary object registry, so event types such as `constructor` and `__proto__` resolve inherited values and throw during registration. Initialize and reset the internal registry without a prototype, and cover registration, emission, counting, and full reset for both keys.

Fixes #58228.

## Changelog:

[GENERAL] [FIXED] - Support EventEmitter event names that overlap Object prototype properties.

Pull Request resolved: #58229

Test Plan:
- Exact upstream regression: 20 passed / 1 failed at `registrations.add`.
- Fixed Fantom suite: 21/21 passed.
- Fresh `yarn flow-check`: 0 errors.
- Targeted no-ignore ESLint, Prettier, and `git diff --check` passed.

No UI change; screenshots are not applicable.

Reviewed By: cortinico

Differential Revision: D118267117

Pulled By: javache

fbshipit-source-id: 12c3aab577ec13dabe475409ae6e21f5e6853135

Author: OskarEichler

packages/react-native/Libraries/vendor/emitter/EventEmitter.js

@@ -84,7 +84,7 @@ export default class EventEmitter<
 
   constructor() {
     // $FlowFixMe[incompatible-type]
-    this.#registry = {};
+    this.#registry = Object.create(null);
   }
 
   /**
@@ -147,7 +147,7 @@ export default class EventEmitter<
   ): void {
     if (eventType == null) {
       // $FlowFixMe[incompatible-type]
-      this.#registry = {};
+      this.#registry = Object.create(null);
     } else {
       // $FlowFixMe[cannot-write]
       delete this.#registry[eventType];

packages/react-native/Libraries/vendor/emitter/__tests__/EventEmitter-itest.js

@@ -57,6 +57,27 @@ describe('listeners', () => {
     expect(listenerB).toHaveBeenCalledTimes(1);
   });
 
+  it('supports event types that match Object prototype keys', () => {
+    const emitter = new EventEmitter<Readonly<Record<string, []>>>();
+
+    const constructorListener = jest.fn();
+    const protoListener = jest.fn();
+    emitter.addListener('constructor', constructorListener);
+    emitter.addListener('__proto__', protoListener);
+
+    emitter.emit('constructor');
+    emitter.emit('__proto__');
+
+    expect(constructorListener).toHaveBeenCalledTimes(1);
+    expect(protoListener).toHaveBeenCalledTimes(1);
+    expect(emitter.listenerCount('constructor')).toBe(1);
+    expect(emitter.listenerCount('__proto__')).toBe(1);
+
+    emitter.removeAllListeners();
+    expect(emitter.listenerCount('constructor')).toBe(0);
+    expect(emitter.listenerCount('__proto__')).toBe(0);
+  });
+
   it('invokes listeners in registration order', () => {
     const emitter = new EventEmitter<{A: []}>();