Summary: We may wish to perform some additional computation on values when they enter or exit the memo cache in change detection mode (e.g. make a deep copy, restore the original value). This builds support for doing so.
In addition, it drops the "ForDebugging" part of the flag name and makes it compatible with "disableMemoization": if memoization is disabled, we implement that by not restoring the old version of the value unless we're in a source-level memo block.
[ghstack-poisoned]
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