This reverts commit 5d4a0903.

Reason for revert: Speculative revert due to timeouts on testing with
--isolates:
https://build.chromium.org/p/client.v8/builders/V8%20Linux/builds/21889
https://build.chromium.org/p/client.v8/builders/V8%20Linux%20-%20debug/builds/18138

Original change's description:
> Add support to produce code cache after execute.
> 
> Adds new API function to request code cache. Earlier code cache was
> produced along with compile requests. This new API allows us to request
> code cache after executing. Also adds support in the code serializer to
> serialize after executing the script.
> 
> Bug: chromium:783124
> Cq-Include-Trybots: master.tryserver.chromium.linux:linux_chromium_rel_ng
> Change-Id: Id7b972a2b4c8dcf7a6d9f5ea210890ae968320bd
> Reviewed-on: https://chromium-review.googlesource.com/781767
> Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
> Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
> Reviewed-by: Yang Guo <yangguo@chromium.org>
> Commit-Queue: Mythri Alle <mythria@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#49717}

TBR=ulan@chromium.org,rmcilroy@chromium.org,yangguo@chromium.org,mythria@chromium.org

Change-Id: Id9e0285e73bbc3ea3908b4b7bbf6599e4f7cd76e
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: chromium:783124
Cq-Include-Trybots: master.tryserver.chromium.linux:linux_chromium_rel_ng
Reviewed-on: https://chromium-review.googlesource.com/796870Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Commit-Queue: Michael Achenbach <machenbach@chromium.org>
Cr-Commit-Position: refs/heads/master@{#49722}