This CL is part of a series that adds the C++ implementation of
SwissNameDictionary, a deterministic property backing store based on
Swiss Tables.

This CL add the lookup and iteration functions as well as the helpers
needed for that.

Bug: v8:11388
Change-Id: Ib684f32d1623868f9caf79c48fc61478d6f6ee4b
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2695391Reviewed-by: Igor Sheludko <ishell@chromium.org>
Reviewed-by: Marja Hölttä <marja@chromium.org>
Commit-Queue: Frank Emrich <emrich@google.com>
Cr-Commit-Position: refs/heads/master@{#72940}