Use latest revision for dependencies on interned values

[ibraheemdev]

Resolved #904.

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[codspeed-hq]

CodSpeed Performance Report

Merging #908 will not alter performance

_{Comparing ibraheemdev:ibraheem/interned-dependencies (898343c) with master (8924db1)}

Summary

✅ 12 untouched benchmarks

[MichaReiser]

I think this change technically means that, for any query creating or depending on a query creating interned values, this path can no longer be taken.

https://github.com/MichaReiser/salsa/blob/8d3455f0e6451c0dd6f88412db2aa9c49f41bc3f/src/function/maybe_changed_after.rs#L169-L176

Ideally, we'd use first_interned_at because that's since when this query hasn't changed. But we no longer track this for interned values. We could use last_interned_at (before it gets updated) but that seems a bit hacky because it only does the "backdating" for the query first validating the interned value.

Maybe something to discuss during todays meeting: Whether we want to bring back first_interned_at or if there's another way to avoid using current_revision here.

[ibraheemdev]

I wasn't sure if first_interned_at was correct even for this case, but I agree that it is, because if the slot was recreated in a new revision because of garbage collection that must have happened after the initial creation, which is sufficient to update the memo.