enum addMember | insertMember

Version: 21.0.1

while i want to add [insertA,insertB] in EnumA,
the result to be inserted appears in the wrong line

EnumDeclaration.insertMember() and EnumDeclaration.addMember() is same results

before:
```ts
export enum EnumA {
//
a,
//
b,
//
c,
d,
e,
f,
}
```

after:
```ts
export enum EnumA {
//
a,
//
b,
//
c,
insertA,
insertB,
d,
e,
f,
}
```
i guess the problem is three line comments

Start by reproducing the EnumDeclaration.insertMember() and addMember() behavior with the enum shown in the issue, including the three line comments. Read the enum member insertion implementation and its related tests, then verify that inserting insertA and insertB places them between c and d without disturbing the comments.

Written by the indexing model from the issue text.