Fixes a worst-case behavior in the getLaterBaseAccess predicate by using SSA variables.

Gets the worstcase performance down from 20 minutes (on my laptop), down to milliseconds.
It was causing timeouts on some smaller runners.

Also somehow fixed a missing result that I apparently missed when I first implemented GetLaterAccess 🤷

TODO: Evaluations: nightly, problematic, default.

Problematic project:

metafloor/bwip-js (regress with SSA)
varemenos/codemagic (regress with SSA, smaller)
aakashjhawar/commercial-centers-using-POI (regress before SSA)