Extract the structural+demand classification out of main.ml's typecheck_all
into `Gcinfer.infer : parsed -> symbols -> symbols`, so a single library entry
point runs the whole pass. The driver calls it once (before typecheck); the
unit-test helpers can call the same function, so is_gc_class classifies
identically in the binary and in tests (prerequisite for removing the @gc
keyword, whose tests read the golden fixtures through the library directly).
- dune: gcinfer moved after owner (it now runs ownership in collect mode).
- main.ml typecheck_all: the split structural-inject + post-typecheck demand
loop become one `Gcinfer.infer parsed syms` call.
- Documented the known demand-promotion imprecision (promotes the escaping root
local's class, over-promoting the container) to refine with Phase 3.
Behavior-neutral: woc-test 566/0, test_diag 14/0, oop-e2e 79/0.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>