Fix export default expression comment

[xiaoxiangmoe]

Fixes #48305

[Kingwl]

LGTM

[sandersn]

this is probably a question for @rbuckton , but why do you need to removeAllComments(input)? The other uses of preserveJSDoc don't do that.

[sandersn]

I have a question about why removeAllComments is needed.

[Kingwl]

I have a question about why removeAllComments is needed.

The Input is still in the output code. And the preserveJsDoc will not remove the original comments.
It's will be duplicated if we don't remove the comments.

[xiaoxiangmoe]

@sandersn

If I add removeAllComments(input);, it will be

/**
 * JSDoc Comments
 */
declare const _default: any;
export default _default;

If I remove removeAllComments(input);, it will be

/**
 * JSDoc Comments
 */
declare const _default: any;
/**
 * JSDoc Comments
 */
export default _default;