edge case: Valueless option with async work duplicates (async) work

[elliott-with-the-longest-name-on-github]

Describe the bug

<option>{await work()}</option> duplicates the call to work because it injects a synthetic value attribute which just has the copied contents of the child expression. This wasn't a big deal in sync-land but async-land means much bigger duplication consequences. The fix isn't very complicated in practice; we basically "just" need to hoist the expression tag such that the compiled code does this instead:

const promise = work();
<option value={await promise}>{await promise}</option>

Reproduction

https://svelte.dev/playground/hello-world?version=5.38.6#H4sIAAAAAAAAE23MPQuDMBSF4b8S7qKC6B6s0K1j99ohNccSuCZirtoi_vdiP7auL885K3nTgzSdwBzUEka2KoV1AptRTp1jRNKXleQ57G4PlP9Wx2Eo4gyWvd1MxL_eBi_wEklTFcFoRc2GJxzWxIZ7stWNV6oKg7jg69Usxok6j6F3EcWIGHhG-pbZVpVf1viq_HzVjaecBA8hLeOE7ZqTGMeL85Z0ZzhiewHaa9SD5gAAAA==

Logs

System Info

nty

Severity

annoyance

[Github11200]

Hello! I'm interested in working on this issue if possible. I was wondering if this issue is originating from the parsing step in the compiler or do you think it's coming from elsewhere?

[elliott-with-the-longest-name-on-github]

It's in both the analysis phase and the compilation phase but I've already fixed it as part the work on async SSR!