JSFunctionData has a fairly heavy serialized payload, and likewise
consistency validation validates many fields and thus has many
opportunities to fail. We therefore want to avoid or reduce validation
whenever possible.

This CL adds tracking s.t. we know which fields were actually used,
and we limit validation to used fields.

Drive-by: Make serialized_ debug-only.
Drive-by: Don't create deps for context/native_context/shared.

Bug: v8:7790
Change-Id: Ic32c9919f0c75a76d9c36e4396b6bce383151b62
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3132962
Commit-Queue: Jakob Gruber <jgruber@chromium.org>
Reviewed-by: Georg Neis <neis@chromium.org>
Cr-Commit-Position: refs/heads/main@{#76614}