gap-suite full mode: builtin-construct trio fails under auto-optimize but passes fast mode (blocks full-suite-gate) #8223

In the tiered CI (#8187) the gap suite runs in two modes against the same test-parity/gap_snapshot.json: fast (PERRY_SKIP_BUILD=1, prebuilt archives — PR/sweep tiers) and the harness default auto-optimize (full tier, 8 shards). First full-tier run (31935729773):

• shard 2: test_gap_dynamic_builtin_construct_dispatch pass -> parity_fail
• shard 3: test_gap_new_globalthis_builtin_6726 pass -> parity_fail
• shard 7: test_gap_builtin_alias_construct_7524 pass -> parity_fail

All three PASS in fast mode on the same commit (PR run 31940422482, all 6 shards green). So this is an auto-optimize-link-specific regression in the builtin construct-dispatch family — the same trio #8117 flagged (closed when #8198 fixed the snapshot side; the auto-optimize arm is still red). Suspects from the 08-15/16 window per #8117: #8183, #8165, #8094.

Until fixed this keeps full-suite-gate (the release gate) red.