We already make code pages writable & executable for concurrent
Sparkplug. We can use the same mechanism for sweeping of code pages on
the background thread, instead of scheduling incremental tasks on the
main thread. This allows us to remove almost all special
handling for code pages in the sweeper and allows us to off-load more
work from the main thread.

Bug: v8:12967
Change-Id: Idb8e9f8e2eadbec26a386f2de683a80087f671f3
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3695557Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Commit-Queue: Dominik Inführ <dinfuehr@chromium.org>
Cr-Commit-Position: refs/heads/main@{#81139}