Stripping types should include ts-ignore comments

TypeScript Version: 3.8 latest, playground

Search Terms: remove ts-ignore comment

Code

// this is a comment that should be kept
const message: string = 'hello world';
// the below ts-ignore comment should be removed, since it has no meaning in a non-TS context
// @ts-ignore
console.log(message);

Expected behavior:
ts-ignore comment is stripped, other comments are kept.

Actual behavior:
all comments are kept including ts-ignore comments.

Playground Link: https://www.typescriptlang.org/play/#code/PTAEBcAsEsGdTqAhqAxgewLaYKYDtwJIlDZJ0BXAGwBNQAjHUAaxwAdwAoDPWQ3WLCQBzHAC5QfAE7Q8w0AF5QAckg4qVdKADu6KbWUBuTiCJNGm7RFgBaaMLx6mGbPlLlqJsAAFwt+45SONzovOhUOAB0msIAFAJCogCUhkA

Related Issues:

リンク先の TypeScript Playground で例を再現し、出力された JavaScript を期待される動作と比較します。型とコメントの削除を担うコンパイラーパスを追跡し、その後、通常のコメントが残る一方で @ts-ignore が削除されることを確認します。