The N_INDEX node carries the checker-stamped element tinfo (#60 arc); cgindex,
cgun TK_AMP, and cgassign now read the element stride off that .type_.size
instead of indexbaseesz's manual N_DOT-pseudo-field + structlookup walk,
retiring the helper (0 callers, ~96 LOC). Aligns down to cstage's
idx_eff(base->type)->sub->size (cmd/w6c/cgen.c:3517-18, natural element size) --
strictly more cstage-faithful than indexbaseesz's totsize/slotsize derivation
(byte-id held only because firing shapes have totsize==natural; cstage reads
natural and ww-old==cstage, so the flip is structural). Each site keeps its
nil->default-8 fallback; cgindex stays esz-only (signed_elem unset for the
N_DOT base, as before).
Closes the A.6.3 cgenutil-collapse arc: every type/size/offset query in cgen
now reads the checker-stamped tinfo, and the AST-walker / structinfo-walk
helpers it replaced (dotfieldtnode, indexvaluetnode, rhstargetname,
dotinnerstructptr, indexbaseesz) are retired. make test 134/134, byte-id
990-997 hold. Coverage: 713/741/755 + self-rebuild.
Hojun-Cho
f45caf1cd9