Missing computed properties in declaration emit

With #60052, we now emit qualified names rather than generate an index signature for computed names in classes; however, this now puts us in an awkward place where regardless of errors, declaration emit diverges on isolatedDeclarations.

Playground Links:

• 5.7, without isolatedDeclarations
• Nightly, without isolatedDeclarations
• Nightly, with isolatedDeclarations

export const greeting: unique symbol = Symbol();
export const count: unique symbol = Symbol();

export class MyClass1 {
    [greeting]: string = "world";
    [count]: number = 42;
}

export enum PropertyNames {
    greeting = "greeting",
    count = "count",
}

export class MyClass2 {
    [PropertyNames.greeting]: string = "world";
    [PropertyNames.count]: number = 42;
}

export let prop!: string;

export class MyClass3 {
    [prop]: () => void = () => {}
}

Compared to --isolatedDeclarations false The declaration emit lacks expected contents in MyClass1 and MyClass2:

  export declare const greeting: unique symbol;
  export declare const count: unique symbol;
  export declare class MyClass1 {
-     [greeting]: string;
-     [count]: number;
  }
  export declare enum PropertyNames {
      greeting = "greeting",
      count = "count"
  }
  export declare class MyClass2 {
-     [PropertyNames.greeting]: string;
-     [PropertyNames.count]: number;
  }
  export declare let prop: string;
  export declare class MyClass3 {
      [prop]: () => void;
  }

It is surprising that prop is emitted regardless of --isolatedDeclarations, but not the other contents.

Playground のリンクで示されている TypeScript の declaration emit の動作から始め、MyClass1、MyClass2、MyClass3 について --isolatedDeclarations を付けた場合と付けない場合の出力を比較します。computed property の処理を追跡し、現在の prop の動作を維持しながら、declaration emit が期待される computed property を保持するようにします。出力された declaration の差分を例と照合して確認します。