This reverts commit a1b431d7.

Reason for revert: https://ci.chromium.org/p/v8/builders/luci.v8.ci/V8%20Linux%20-%20nosnap%20-%20debug/22809

Original change's description:
> [serializer] share class positions tuple across contexts
> 
> Class positions is a struct that stores the start and end positions of a class
> literal. It is stored both on class objects, and the template used to
> instantiate class objects.
> 
> The template is reachable from the bytecode array and therefore serialized by
> the startup serializer. Class objects are context-dependent and therefore
> serialized by the partial serializer. Serializing class positions from both
> serializers violates the assumption that we don't serialize any object twice.
> 
> R=​gsathya@chromium.org
> 
> Bug: v8:8761
> Change-Id: If22c554cc7396d63998a015454ce0c67a7d2e05c
> Reviewed-on: https://chromium-review.googlesource.com/c/1444956
> Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
> Reviewed-by: Sathya Gunasekaran <gsathya@chromium.org>
> Commit-Queue: Yang Guo <yangguo@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#59292}

TBR=yangguo@chromium.org,mstarzinger@chromium.org,gsathya@chromium.org

Change-Id: I9f3fd1b29b5991b450223f8b27dfc7aa7e5a3171
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: v8:8761
Reviewed-on: https://chromium-review.googlesource.com/c/1450116Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Commit-Queue: Michael Starzinger <mstarzinger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#59300}