`{@debug}` of an awaited expression yields an error

[Tinggaard]

Describe the bug

If you pass an awaited expression to a {@debug ...} statement, it will error.

I found the bug while investigating a regression in our app introduced in 5.55.3 (unrelated to this issue - still trying to reproduce).

Related: #18024

Reproduction

REPL

<svelte:boundary>
	{@const data = await Promise.resolve("works")}
	{@debug data}
</svelte:boundary>

Logs

System Info

.

Severity

annoyance

[GrygrFlzr]

Doing a quick binary search, it seems the last version this code sample ran without complaint was 5.43.8, and 5.43.9 introduced the current behavior, so probably one of the PRs related to that are involved.