transpileOnly : true will make const enum not work

[xiaopingbuxiao]

Expected Behaviour

when I use transpileOnly : true , const enum will not work。 I think it is reasonable, but it would be good if had a description in the document

Actual Behaviour

//  test.d.ts
declare namespace Test {
  export const enum Hello {
    Hello = 1
  }
}

// index.ts

console.log(Test.Hello.Hello)

Steps to Reproduce the Problem

Location of a Minimal Repository that Demonstrates the Issue.

[xiaopingbuxiao]

https://github.com/TypeStrong/ts-loader/issues/331