- Adds IsGarbageCollectedWithMixin<T> to check for mixin applications.
- Add documentation to all trait values.

Bug: chromium:1056170
Change-Id: I22c255c36c791a5ff9b38d034f205f1e23c968ca
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2644951Reviewed-by: Omer Katz <omerkatz@chromium.org>
Commit-Queue: Michael Lippautz <mlippautz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#72268}

The TraceTrait<T> checks whether T is a mixin to decide whether we can
use the fast (arithmetic) or slow (bitmap) method to look up the HoH.
Before this CL, the mixin application would also be considered as a
mixin because the marker is present, resulting in all cases going
through the object start bitmap.

The initial intention was to use the arithmetic for the mixin
applications as those inherit from GCed.

Bug: chromium:1056170
Change-Id: Ib0ba82a8f98e0481d2879ebacc1ca9bd9e675858
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2643395
Commit-Queue: Michael Lippautz <mlippautz@chromium.org>
Reviewed-by: Omer Katz <omerkatz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#72262}

Adds traits for checking for Member,WeakMember, and UntracedMember
types.

This allows the embedder to specify its own traits and restrictions
around cppgc types.

Bug: chromium:1056170
Change-Id: Ibe60b774128f72f1398267edd81233c50fca6eb7
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2532299Reviewed-by: Omer Katz <omerkatz@chromium.org>
Commit-Queue: Michael Lippautz <mlippautz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#71121}

Bug: chromium:1056170
Change-Id: Ifc519559868d9c3099d309f75ba8faf2018a1578
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2154951
Commit-Queue: Omer Katz <omerkatz@chromium.org>
Reviewed-by: Anton Bikineev <bikineev@chromium.org>
Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#67235}

This change comprises a few tiny changes wrt Member:
1) Move member policies to a separate file so that some of them
(CheckingPolicy) can be reused by Persistent;
2) SFINAE out incompatible pointers from heterogeneous ctor/asgnmt;
3) Rename kMemberSentinel to kSentinelPointer.

Bug: chromium:1056170
Change-Id: I4482998e6ba61005a5d0861dcae9fab2aa43702c
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2139587Reviewed-by: Omer Katz <omerkatz@chromium.org>
Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Commit-Queue: Anton Bikineev <bikineev@chromium.org>
Cr-Commit-Position: refs/heads/master@{#67061}

This CL adds the necessary traits to dispatch from Member through a
visitor implementation for GarabgeCollected and GarbageCollectedMixin.

Bug: chromium:1056170
Change-Id: I12680335044aaa842639fb5e8f9a3ac61587f51a
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2138431Reviewed-by: Hannes Payer <hpayer@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Reviewed-by: Omer Katz <omerkatz@chromium.org>
Reviewed-by: Anton Bikineev <bikineev@chromium.org>
Commit-Queue: Michael Lippautz <mlippautz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#67041}