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 contains:
1. Copy and equality functions used for testing
2. Runtime functions corresponding to most dictionary operations,
   which are used temporarily while the CSA/Torque implementation
   is work in progress
3. Some minor changes to SwissNameDictionary needed for testing
   (adding template instantiations, V8_EXPORT_PRIVATE, ...)

Bug: v8:11388
Change-Id: Iea5f4650b0a443edf563565138ea86fcb45af13a
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2722094
Commit-Queue: Frank Emrich <emrich@google.com>
Reviewed-by: Igor Sheludko <ishell@chromium.org>
Reviewed-by: Marja Hölttä <marja@chromium.org>
Cr-Commit-Position: refs/heads/master@{#73153}