Hojun-Cho
7589b1bf0b
The wwstage checker silently accepted enums with a non-integer storage type, duplicate members, or a non-constant member value; cstage already rejects all three (cmd/wcc/check.c:1000-1042). Add validateenummembers, a pure read-only diagnostic dispatched once per enum decl from resolvewalk's N_TENUM arm (check.ww:791, beside stampenumvals -- not the per-query recompute arms), mirroring the catB-7/14 validatestructfields pattern. Storage gate uses typeisint on the resolved tinfo (the exact type_isint mirror: chases TY_NAMED.under and TY_ENUM.sub, so an int-alias storage is accepted; raw-AST isinttypeast would not). Duplicate members: O(n^2) name walk. Unfoldable values reuse enumvalfold with until=member (forward-only). Emits via cerr + c.errs, no mutation, so valid-program codegen is unchanged and cstage==wwstage byte-id holds. wwstage's value-fold message is intentionally generic where cstage's eval_enum_value gives per-reason text (enumvalfold returns a bool, not a reason); both reject. Documented at the site, filed as follow-up task #10. Test: new table-driven both-stage reject test 850_enum_reject (non-int storage / duplicate member / forward-ref rows + a distinct-member control whose backward-ref value builds and runs). Full make test: 452 green incl. 990-997 byte-id.