Maglev double registers spill can use simple size kDoubleSize even
when wasm is enabled.

Bug: v8:7700
Change-Id: I485f69eeda781dddcbac4d34018b4442b6eb529d
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3789382Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Auto-Submit: Victor Gomes <victorgomes@chromium.org>
Commit-Queue: Leszek Swirski <leszeks@chromium.org>
Cr-Commit-Position: refs/heads/main@{#81998}