[Compiler Bug]: `using` syntax is not preserved

### What kind of issue is this? - [x] React Compiler core (the JS output is incorrect, or your app works incorrectly after optimization) - [ ] babel-plugin-react-compiler (build issue installing or using the Babel plugin) - [ ] eslint-plugin-react-hooks (build issue installing or using the eslint plugin) - [ ] react-compiler-healthcheck (build issue installing or using the healthcheck script) ### Link to repro https://github.com/cormacrelf/react-compiler-using-bug ### Repro steps `pnpm i && pnpm dev`. Open App.tsx to see there are three [diposables with `using` syntax](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/using). Open the console, note that only one of the Disposables had its `Symbol.dispose` method called. To show that it's react-compiler's fault, you can: - observe that only `using` syntax inside the component is transformed, the one at the top level is preserved. - uncomment `effect.useIt()` which makes react-compiler skip the component and all the disposals work. - skip the component - disable the transform in vite.config.ts Note that react-compiler transforms the `using render = new Disposable("render");` to just `new Disposable("render")`, which is not a valid transform. It would be valid for a `const` or `let` binding. There is another bug in here that I can't reproduce, because react-compiler keeps bailing out when I add the `useIt` call. But very similar code to the following *does* get compiled, and in that case the using is just transformed to a const, which again breaks the disposal. ```typescript function App() { const context = useContext(); const ref = React.useRef(null); useEffect(() => { if (ref.current) { using effect = new Disposable(context); effect.useIt(); } }); return <div ref={ref}></div>; } ``` ### How often does this bug happen? Every time ### What version of React are you using? 19.2.0 ### What version of React Compiler are you using? 1.0.0