Declaration emit differs for negative numeric const literals

@jakebailey arbeitet bereits daran.

Seit 01.6.2026.

• #4158 von @copilot-swe-agent — ohne Merge geschlossen

## Steps to reproduce

`main.ts`:
```ts
export const a = -1e500 as const;
export const b = -123456789012345678901234567890 as const;
```

```sh
tsgo --declaration main.ts
```

## Behavior with `typescript@6.0`

```ts
export declare const a: -1e500;
export declare const b: -123456789012345678901234567890;
```

## Behavior with `tsgo`

```ts
export declare const a: -Infinity;
export declare const b: -1.2345678901234568e+29;
```