No Error for use before def in property initializer

Seems https://github.com/Microsoft/TypeScript/pull/17910 broke one of our RWC tests (see Azure_FrameworkTests.errors).

here is the jest:

```ts
	export class C {
		public a =  {
			b: this._b // No Error here for use before declaration.
		};

		private _b = "";
	}
```