... as it uniquely idenifies object inside an Isolate.
This also allows comparisons between full tagged values ([Maybe]Object)
and potentially compressed tagged values ([Strong]TaggedValue).

As a side effect with this change we should generate a bit less code.

Bug: v8:7703
Change-Id: I822df24e03653fa73314e0a6f81f0fa7b5c61eba
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1643433Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Commit-Queue: Igor Sheludko <ishell@chromium.org>
Cr-Commit-Position: refs/heads/master@{#61998}