doc: https://docs.google.com/document/d/1Y9uF3hS2aUrwKU56vGxlvEs_IiGgmWSzau8097Y-XBM/edit

Bug: v8:7427
Change-Id: Iedd36c146cefff7e6687fdad48d263889c5c8347
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1778902
Commit-Queue: Ross McIlroy <rmcilroy@chromium.org>
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Reviewed-by: Toon Verwaest <verwaest@chromium.org>
Cr-Commit-Position: refs/heads/master@{#63913}