This CL doesn't try to compress containers of Node* yet.

Bug: v8:9923
Change-Id: Ica16b09b6f26321952b440d49a70f9a991d4275f
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2324258
Commit-Queue: Igor Sheludko (OOO Aug 3-17) <ishell@chromium.org>
Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#69168}