Serialization symbol cannot be written on object ({attack:["Unit", "Structure"]}) rP24551

[Silier]

It happens after using attack-move replay with D3225

[Silier]

possible causes rP24462 or rP24167

[wraitii]

Fixed by both D3334 and D3336 in different ways.

[wraitii]

In 24563:

Revert rP24167 / Keep track of serialized objects using a GCHashTable

This reverts rP24167. That diff had two issues:

• It modifies the JS objects, which means subsequent serialization in quicksave are 'dirty'.
• It doesn't work with non-extensible objects. That's rather annoying, and has already caused problems.

It also revert rP24466, which was necessary because of the second issue.

Fixes #5908

Differential Revision: ​https://code.wildfiregames.com/D3336