When v8_enable_external_code_space is enabled the Code objects are
allowed only
- in CodeDataContainer::code field
- as uncompressed values embedded in Code instruction streams

Bug: v8:11880
Change-Id: I080a678fd77a7e42c6a397e7145a640fd07d6e83
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2969828Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Commit-Queue: Igor Sheludko <ishell@chromium.org>
Cr-Commit-Position: refs/heads/master@{#75275}