Swift: Update SSA to reference the new use-use predicates.

[aschackmull]

Something about the use-use steps in data flow looks buggy, but I'm not going to fix that here. This is just aiming for a one-for-one semantically equivalent switch to the new use-use predicates.

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[aschackmull]

It appears that the changes do improve flow slightly - enough to fix a missing flow in a test.

[geoffw0]

DCA is showing two new results (👍) but a slowdown in analysis times, including one project apparently timing out during analysis.

[aschackmull]

DCA is showing two new results

I don't see this? (neither in the first nor second dca run)

but a slowdown in analysis times, including one project apparently timing out during analysis.

Did you look at the second dca run? I fixed an accidental CP and reran dca, so there shouldn't be any timeouts.

[aschackmull]

I also cannot reproduce any of the supposed timing regressions in the second dca run locally, so I'm leaning towards considering those numbers noise.

[paldepind]

Looks good to me. Regarding the DCA slowdown, 1/3 of the projects got faster and the remaining 2/3 got slower. So I agree that it is very likely just noise.