This method is called in the critical section in {PublishCode}, hence
performance is important here. Since most modules will only have a
single code space anyway, we can use the main jump table in the vast
majority of cases, and avoid taking a lock and iterating another data
structure.

R=ahaas@chromium.org

Bug: v8:10330
Change-Id: I18cbd3b127172963ccc9ec576a0985e874da7865
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2104891
Commit-Queue: Clemens Backes <clemensb@chromium.org>
Reviewed-by: Andreas Haas <ahaas@chromium.org>
Cr-Commit-Position: refs/heads/master@{#66721}