One of the biggest categories in heap snapshots is named “(system)”,
which gives developers no indication of why all that memory is used or
what they might do to reduce it. In this change, I propose that we
create a new category for Maps, DescriptorArrays, and related objects,
and call this new category “(object shape)” in the devtools. I think
that this category name would be more meaningful, while still grouping
those objects together so that they mostly stay out of the way.

Bug: v8:12769
Doc: https://docs.google.com/document/d/1a-6V_2LIJuRcsppwh6E18g8OSnC9j6gN4ao2gq--BiU
Change-Id: I282a7b87c34ca6ed371ff32f3c7332d794ae42ca
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3587974Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Reviewed-by: Camillo Bruni <cbruni@chromium.org>
Commit-Queue: Seth Brenith <seth.brenith@microsoft.com>
Cr-Commit-Position: refs/heads/main@{#80123}