As part of moving export wrappers to the isolate, it was tried to
compile them lazily on the main thread. This resulted in large
slowdowns in some cases, therefore we restore the eager parallel
compilation.

Bug: chromium:1365726
Change-Id: I9cc8d5728f3a5c71099f0e0fdcc605b37d4d6618
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3905193Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Commit-Queue: Manos Koukoutos <manoskouk@chromium.org>
Cr-Commit-Position: refs/heads/main@{#83339}