Hojun-Cho
df74d9c429
Match-arm bind size in wwstage hardcoded str=16, []T=24, else=8 in both cgmatch (emit) and scanlocals (frame pre-scan). A TY_STRUCT variant fell into the 8B fallback: only the first quadword reached the bind, and the prologue SUBQ underbooked the frame so the emit-time localalloc(bsz=24+) wrote past SP. Replace the hand-rolled table with slotsize(c, pat) at both sites. slotsize already covers N_TNAME named structs (returns si.totsize), str (16), []T (24), tuples, aliases, and primitives (8). Mirrors cstage cgen.c cgmatch which falls through to bu->size for TY_STRUCT. Cstage is correct; no mirror needed. Test 695 covers seven shapes: the 3xi64 headline repro, a 4xi64 struct via let-init scrut (exercises >24B bind), a mixed-quadword struct (i32+i32+i64+i64), str/slice/i32 negative controls, and a direct let-init scrutinee variant. The wider 4xi64 row uses the let-init shape because the N_DOT spill path in cgmatch tops out at AX/DX/CX/R8 — a separate, unrelated gap from the bind size.