Embedder fields are located between JSObject header and inobject fields
and there must be no gaps.
This CL adds respective check to Map verification and fixes existing
issues.

Bug: v8:10391
Change-Id: If55652095588f8704c9a375fb86be1599816aa86
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3482436
Auto-Submit: Igor Sheludko <ishell@chromium.org>
Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Commit-Queue: Igor Sheludko <ishell@chromium.org>
Cr-Commit-Position: refs/heads/main@{#79227}