Re-port the SCI compatibility stress test to joltc: host/chez/run-sci.ss loads
borkdude/sci's own source (vendor/sci, re-vendored) through the spine and
requires its forms to compile+eval. Floor-gated at 160/218 forms (the tail is
genuine host gaps — set! on vars, some macro/def shapes); raise as they close.
Wired into 'make test' (skips if the submodule isn't checked out).
jolt-cf1q.6
