This CL changes the "small" versions of ordered hash tables, like
SmallOrderedNameDictionary and the corresponding handlers, like
OrderedNameDictionaryHandler, to use InternalIndex rather than int
as the type used for indices.

This is part of an effort to make the interfaces of the
ordered and unordered name dictionaries more similar.

Bug: v8:7569
Change-Id: I3b6fe79dfd3c6743f58a04cfe82798fe2ef09e19
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2505720
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@{#70876}