Hojun-Cho
6e7c9e0df4
`type error = !(invalid | overflow)` miscompiled — istaggedtype only matched N_TTAGGED directly, so an `e: error` param spilled as 8B scalar and the match's slot+8 read trailed into saved BP. Mirror isstrtype's alias+bang unwrap; add resolvetagged() for is/as/match sites that need the inner N_TTAGGED. Frame scan counts via slotsize so wwstage stays byte-identical to cstage. Unblocks lib/strconv.strerror.