This saves memory (the home object doesn't need to be stored for each
method, but only once per class) and hopefully makes the home object
a constant in the optimized code.

Detailed documentation of the changes:
https://docs.google.com/document/d/1ZVXcoQdf9IdMsnRI9iyUjyq9NDoEyx9nA3XqMgwflMs/edit?usp=sharing

Bug: v8:9237
Change-Id: Ia0925bdc8bfe54cbefcba6d10f64746d63a530c7
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2563275
Commit-Queue: Marja Hölttä <marja@chromium.org>
Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Cr-Commit-Position: refs/heads/master@{#72137}