This CL adds partial support for objects whose slow mode dictionaries
are OrderedNameDictionaries. This is the case for all slow mode objects
if V8_DICT_MODE_PROTOTYPES is enabled.

Specifically, this CL contains minor changes to CSA code, short of
actually performing ordered dictionary lookups using CSA
implementations of these lookups.

Bug: v8:7569
Change-Id: I0dab0f21000ca3b9b170ace58787ec639d587e64
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2540590
Commit-Queue: Frank Emrich <emrich@google.com>
Reviewed-by: Marja Hölttä <marja@chromium.org>
Reviewed-by: Igor Sheludko <ishell@chromium.org>
Reviewed-by: Dominik Inführ <dinfuehr@chromium.org>
Cr-Commit-Position: refs/heads/master@{#71304}