This is no longer useful since the SerializeForBackgroundCompilation is
gone.

Bug: v8:7790
Change-Id: Icb4858a5863daca740fc13c52b7ee0bb7ec0f155
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3081608Reviewed-by: Santiago Aboy Solanes <solanes@chromium.org>
Commit-Queue: Georg Neis <neis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#76167}