Original commit message:

    [cppgc] expose wrapper descriptor on CppHeap

    This makes it possible for embedders to:

    1. Avoid creating wrapper objects that happen to have a layout that
      leads V8 to consider the object cppgc-managed while it's not.
      Refs: nodejs#43521
    2. Create cppgc-managed wrapper objects when they do not own the
       CppHeap. Refs: nodejs#45704

    Bug: v8:13960
    Change-Id: If31f4d56c5ead59dc0d56f937494d23d631f7438
    Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/4598833
    Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
    Commit-Queue: Michael Lippautz <mlippautz@chromium.org>
    Cr-Commit-Position: refs/heads/main@{#88490}

Refs: v8/v8@9327503
PR-URL: nodejs#48660
Reviewed-By: Chengzhong Wu <legendecas@gmail.com>
Reviewed-By: Jiawen Geng <technicalcute@gmail.com>

Previously we hard-code a wrapper id to be used in BaseObjects
to avoid accidentally triggering cppgc on these non-cppgc-managed
objects, but hard-coding can be be hacky and result in mismatch
when we start to create CppHeap ourselves. This patch makes it
more robust by deducing non-cppgc id from the effective cppgc id,
if there is one.

PR-URL: nodejs#48660
Refs: v8/v8@9327503
Reviewed-By: Chengzhong Wu <legendecas@gmail.com>
Reviewed-By: Jiawen Geng <technicalcute@gmail.com>

This patch:

- Initializes cppgc in InitializeOncePerProcess() when
  kNoInitializeCppgc is not set
- Create a CppHeap and attach it to the Isolate when
  there isn't one already during IsolateData initialization.
  The CppHeap is detached and terminated when IsolateData
  is freed.
- Publishes the cppgc headers in the tarball.

This allows C++ addons to start using cppgc to manage objects.

A helper node::SetCppgcReference() is also added to help addons
enable cppgc tracing in a user-defined object.

Co-authored-by: Joyee Cheung <joyeec9h3@gmail.com>
Refs: nodejs#40786
PR-URL: nodejs#45704
Refs: https://docs.google.com/document/d/1ny2Qz_EsUnXGKJRGxoA-FXIE2xpLgaMAN6jD7eAkqFQ/edit
Reviewed-By: Stephen Belanger <admin@stephenbelanger.com>
Reviewed-By: Rafael Gonzaga <rafael.nunu@hotmail.com>

This patch:

- Initializes cppgc in InitializeOncePerProcess() when
  kNoInitializeCppgc is not set
- Create a CppHeap and attach it to the Isolate when
  there isn't one already during IsolateData initialization.
  The CppHeap is detached and terminated when IsolateData
  is freed.
- Publishes the cppgc headers in the tarball.

This allows C++ addons to start using cppgc to manage objects.

A helper node::SetCppgcReference() is also added to help addons
enable cppgc tracing in a user-defined object.

Co-authored-by: Joyee Cheung <joyeec9h3@gmail.com>
Refs: #40786
PR-URL: #45704
Backport-PR-URL: #49187
Refs: https://docs.google.com/document/d/1ny2Qz_EsUnXGKJRGxoA-FXIE2xpLgaMAN6jD7eAkqFQ/edit
Reviewed-By: Stephen Belanger <admin@stephenbelanger.com>
Reviewed-By: Rafael Gonzaga <rafael.nunu@hotmail.com>
PR-URL: #48660
Refs: v8/v8@9327503