fix(turbopack-trace-utils): skip the ctrl-c handler on wasm (#97856)
> Replaces #97582, which was **not merged**. Reordering this stack
briefly left that PR
> pointing at a base branch that had come to contain its own head
commit, so GitHub closed it
> as merged and deleted its branch. Nothing from it reached `canary`. It
had been approved;
> this PR is the same commit (`8f8bc4d0b0`), restored, and needs review
again. Sorry for the churn.
### What?
`turbopack-trace-utils` no longer registers a Ctrl-C handler on wasm
targets.
### Why?
`tokio::signal` does not exist on wasi, so `exit.rs` failed to compile.
There is also no SIGINT to
wait for inside a wasm instance, so there is nothing to handle.
### How?
The `tokio::spawn` calls in `ExitGuard::new` and `ExitHandler::listen`
are gated to non-wasm. On
wasm, `ExitGuard` fires only when the guard is dropped, and
`ExitHandler::listen` registers no
handler — the doc comments now say so, and point wasm callers at
`ExitHandler::new_receiver`.
<!-- NEXT_JS_LLM -->
<!-- fleet b6d0486f-97c7-42a7-bdaf-3490774cdec3 -->
Co-authored-by: vercel-fleet-prod[bot] <318278635+vercel-fleet-prod[bot]@users.noreply.github.com>
Co-authored-by: Tobias Koppers <1365881+sokra@users.noreply.github.com>