JavaScript Intellisense doesn't detect types of properties defined in async constructors

# JavaScript Intellisense doesn't detect types of properties defined in async constructors
## Summary
A popular asynchronous constructor pattern in JavaScript is using an async IIFE in the constructor which returns `this` at the end. E.g.
```javascript
constructor() {
return (async () => {
this.#x = 42;
this.y = 42;

return this;
})();
}
```

However, VSCode Intellisense does not infer the types for properties defined in such a constructor.

## Steps to reproduce
1. Open a blank JavaScript, and paste in the following code:
```javascript
class Class1 {
#x;
y;
constructor() {
this.#x = 42;
this.y = 42;
}
}
class Class2 {
#x;
y;
constructor() {
return (async () => {
this.#x = 42;
this.y = 42;

return this;
})();
}
}
```
2. Hover over `y` in `Class1` and observe the tooltip: `(property) Class1.y: number`
3. Hover over `y` in `Class2` and observe the tooltip: `(property) Class2.y: any`

Does this issue occur when all extensions are disabled?: **Yes**

- VS Code Version: 1.97.0
- OS Version: Windows 11

Reproduce the issue in VS Code with the provided Class1 and Class2 examples and compare the hover types with extensions disabled. Trace the TypeScript language-service handling of JavaScript IntelliSense for async constructors, then add regression coverage; done means Class2.y is inferred as number like Class1.y.

Written by the indexing model from the issue text.