The cgindex N_DOT-base arm set esz from the checker-stamped element
tinfo but skipped signedness, so loadopsz saw signed_elem=false and
emitted MOVL/MOVZ* (zero-extend) where cstage's fldloadop reads
signedness from the element type and emits MOVSXD/MOVSWQ/MOVSBQ. A
negative i8/i16/i32 read of `x.o[k]` (struct `[N]T` field) round-tripped
with the wrong upper bits — silent cs!=ww, byte-id-blind since bootstrap
never indexes signed-narrow struct array-fields.
Mirror the sibling N_INDEX-base arm: signed_elem = typeissigned(dt).
loadopsz already keys on (signed,sz), so this closes all three narrow
widths at once. Pure wwstage-up; cstage unchanged.
949 gains nload_i32/i16/i8 negative-read rows (run + cs==ww byte-id).
combined.ww regen'd for w6c + wwdump (the cgen embedders).
Hojun-Cho
d8aaa54b41