fix(turbopack-node): async loop running in loaders worker thread

[xusd320]

Loader's worker should run with an async loop forever, or else, it run only once.

[gemini-code-assist]

Summary of Changes

Hello @xusd320, I'm Gemini Code Assist¹! I'm currently reviewing this pull request and will post my feedback shortly. In the meantime, here's a summary to help you and other reviewers quickly get up to speed!

This pull request addresses a critical bug in Turbopack where loader workers would terminate after a single execution. By refactoring the worker evaluation mechanism and introducing a dedicated TaskChannel for IPC, the changes ensure that workers operate in a persistent, asynchronous loop, significantly improving the stability and continuous processing capabilities of Turbopack's build system.

Highlights

• Worker Persistence Fix: The primary change ensures Turbopack's loader workers run in a continuous asynchronous loop, resolving an issue where they would only execute once.
• IPC Refactoring: Introduces a new TaskChannel class to centralize and streamline inter-process communication (IPC) logic within worker threads.
• Dependency Update: The Cargo.toml for turbopack-tests is updated to explicitly manage features for turbopack-node, enabling the process_pool feature.

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[gemini-code-assist]

Code Review

This pull request aims to fix an issue where the loader's worker thread only runs once, by introducing an async loop. The refactoring of IPC logic into a TaskChannel class is a good improvement for code clarity and reusability.

However, I've found a critical issue in the new implementation of the worker loop in both web_worker/evaluate.ts and worker_threads/evaluate.ts. The current logic is likely to cause deadlocks when a worker task needs to communicate back to the main process, as it tries to acquire a new task before the current one is finished with all its communications. I've left detailed comments on the respective files.