an abstraction that hides the details about how embedder data fields are
encoded in EmbedderDataArrays and JSObjects.

Bug: v8:7703
Change-Id: Ic9f6d9511bec557c6671aa6488b9545e353f968c
Reviewed-on: https://chromium-review.googlesource.com/c/1344155
Commit-Queue: Igor Sheludko <ishell@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#57679}