Switch to this: T for MessagePort and immediate subtypes

Should allow more variance in non-immediate subtypes

src/lib/dom.generated.d.ts

@@ -16389,11 +16389,11 @@ interface MessageEventTargetEventMap {
     "messageerror": MessageEvent;
 }
 
-interface MessageEventTarget {
+interface MessageEventTarget<T> {
     /** [MDN Reference](https://developer.mozilla.org/docs/Web/API/DedicatedWorkerGlobalScope/message_event) */
-    onmessage: ((this: this, ev: MessageEvent) => any) | null;
+    onmessage: ((this: T, ev: MessageEvent) => any) | null;
     /** [MDN Reference](https://developer.mozilla.org/docs/Web/API/DedicatedWorkerGlobalScope/messageerror_event) */
-    onmessageerror: ((this: this, ev: MessageEvent) => any) | null;
+    onmessageerror: ((this: T, ev: MessageEvent) => any) | null;
     addEventListener<K extends keyof MessageEventTargetEventMap>(type: K, listener: (this: MessageEventTarget, ev: MessageEventTargetEventMap[K]) => any, options?: boolean | AddEventListenerOptions): void;
     addEventListener(type: string, listener: EventListenerOrEventListenerObject, options?: boolean | AddEventListenerOptions): void;
     removeEventListener<K extends keyof MessageEventTargetEventMap>(type: K, listener: (this: MessageEventTarget, ev: MessageEventTargetEventMap[K]) => any, options?: boolean | EventListenerOptions): void;
@@ -16410,7 +16410,7 @@ interface MessagePortEventMap extends MessageEventTargetEventMap {
  *
  * [MDN Reference](https://developer.mozilla.org/docs/Web/API/MessagePort)
  */
-interface MessagePort extends EventTarget, MessageEventTarget {
+interface MessagePort extends EventTarget, MessageEventTarget<MessagePort> {
     /**
      * Disconnects the port, so that it is no longer active.
      *
@@ -27268,7 +27268,7 @@ interface WorkerEventMap extends AbstractWorkerEventMap, MessageEventTargetEvent
  *
  * [MDN Reference](https://developer.mozilla.org/docs/Web/API/Worker)
  */
-interface Worker extends EventTarget, AbstractWorker, MessageEventTarget {
+interface Worker extends EventTarget, AbstractWorker, MessageEventTarget<Worker> {
     /**
      * Clones message and transmits it to worker's global environment. transfer can be passed as a list of objects that are to be transferred rather than cloned.
      *

src/lib/webworker.generated.d.ts

@@ -2497,7 +2497,7 @@ interface DedicatedWorkerGlobalScopeEventMap extends WorkerGlobalScopeEventMap,
  *
  * [MDN Reference](https://developer.mozilla.org/docs/Web/API/DedicatedWorkerGlobalScope)
  */
-interface DedicatedWorkerGlobalScope extends WorkerGlobalScope, AnimationFrameProvider, MessageEventTarget {
+interface DedicatedWorkerGlobalScope extends WorkerGlobalScope, AnimationFrameProvider, MessageEventTarget<DedicatedWorkerGlobalScope> {
     /**
      * Returns dedicatedWorkerGlobal's name, i.e. the value given to the Worker constructor. Primarily useful for debugging.
      *
@@ -4333,11 +4333,11 @@ interface MessageEventTargetEventMap {
     "messageerror": MessageEvent;
 }
 
-interface MessageEventTarget {
+interface MessageEventTarget<T> {
     /** [MDN Reference](https://developer.mozilla.org/docs/Web/API/DedicatedWorkerGlobalScope/message_event) */
-    onmessage: ((this: this, ev: MessageEvent) => any) | null;
+    onmessage: ((this: T, ev: MessageEvent) => any) | null;
     /** [MDN Reference](https://developer.mozilla.org/docs/Web/API/DedicatedWorkerGlobalScope/messageerror_event) */
-    onmessageerror: ((this: this, ev: MessageEvent) => any) | null;
+    onmessageerror: ((this: T, ev: MessageEvent) => any) | null;
     addEventListener<K extends keyof MessageEventTargetEventMap>(type: K, listener: (this: MessageEventTarget, ev: MessageEventTargetEventMap[K]) => any, options?: boolean | AddEventListenerOptions): void;
     addEventListener(type: string, listener: EventListenerOrEventListenerObject, options?: boolean | AddEventListenerOptions): void;
     removeEventListener<K extends keyof MessageEventTargetEventMap>(type: K, listener: (this: MessageEventTarget, ev: MessageEventTargetEventMap[K]) => any, options?: boolean | EventListenerOptions): void;
@@ -4354,7 +4354,7 @@ interface MessagePortEventMap extends MessageEventTargetEventMap {
  *
  * [MDN Reference](https://developer.mozilla.org/docs/Web/API/MessagePort)
  */
-interface MessagePort extends EventTarget, MessageEventTarget {
+interface MessagePort extends EventTarget, MessageEventTarget<MessagePort> {
     /**
      * Disconnects the port, so that it is no longer active.
      *
@@ -8929,7 +8929,7 @@ interface WorkerEventMap extends AbstractWorkerEventMap, MessageEventTargetEvent
  *
  * [MDN Reference](https://developer.mozilla.org/docs/Web/API/Worker)
  */
-interface Worker extends EventTarget, AbstractWorker, MessageEventTarget {
+interface Worker extends EventTarget, AbstractWorker, MessageEventTarget<Worker> {
     /**
      * Clones message and transmits it to worker's global environment. transfer can be passed as a list of objects that are to be transferred rather than cloned.
      *