Inlining the field accesses make the code simpler by avoiding the
abstraction of the accessor, and makes stepping through the code for
debugging easier.

R=thibaudm@chromium.org

Bug: v8:12330
Change-Id: I51bd0e88baa5ffba5bd4bfcca36e95caab7468c3
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3372913Reviewed-by: Thibaud Michaud <thibaudm@chromium.org>
Commit-Queue: Clemens Backes <clemensb@chromium.org>
Cr-Commit-Position: refs/heads/main@{#78521}