Refresh bench/rc.txt and the benchmark when bendlang/bend#1596 ships #5

bendlang/bend#1596 (perf(c): hoist arm allocations, return through frame addresses, keep escaping fields of borrowed parameters) changes the C that Bend emits, so the term_keep, ctr_take and rfc_seal counts in bench/rc.txt will move.

Status: Lorenzobattistela reviewed it on 2026-10-16; all three points were addressed that day, and the conflicts were fixed on 2026-10-20. It's waiting for a re-review.

Once a Bend release includes it:

• tools/rc.sh on the emitted C of bench/main.bend, against bench/rc.txt; record the change and refresh the baseline.
• tools/bench.sh bench/main.bend old Bend against new, at --threads 1 and on all cores.