Toggling `isolatedModules` in `tsconfig.json` while running the compiler in `watch` mode, doesn't re-emit `const enums`, unlike toggling `preserveConstEnums`, which does

### 🔎 Search Terms

isolatedModules enums not re-emitted on watch mode

### 🕗 Version & Regression Information

Tested on `6.0.1-rc` and `6.0.0-dev.20260309`

I didn't research if this is a regression or not. It may have always been like this but never reported.

### ⏯ Playground Link

_No response_

### 💻 Code

```ts
const enum TestEnum {
a = 1,
b = 3,
c = 5,
}

const x = TestEnum.b
```

### 🙁 Actual behavior

Toggling `isolatedModules` doesn't change the emitted code when running `tsc` in `watch` mode. However, if the compilation is redone, it does re-emit correctly.

### 🙂 Expected behavior

Should modify the emitted code for `const enums` when the option is changed on `watch` mode, since it does change when re-compiling from scratch.

### Additional information about the issue

For comparison, toggling `preserveConstEnums` in `tsconfig.json` does correctly modify the emitted code in `watch` mode.

Clarification: the issue occurs when `preserveConstEnums` is not defined at all in `tsconfig.json`, so the emit behavior for `const enum`s is implicit from it.

Reproduire l’exemple de const enum fourni avec tsc en mode watch, en basculant d’abord isolatedModules, puis preserveConstEnums dans tsconfig.json. Comparer la sortie émise avec une nouvelle compilation, puis suivre la configuration du mode watch et les chemins d’invalidation de l’émission. Le travail est terminé lorsque la modification de isolatedModules entraîne la réémission des const enums sans nécessiter un redémarrage complet.

Rédigé par le modèle d'indexation à partir du texte de l'issue.