The archive walk skipped every member whose header name starts
with '/', which also dropped GNU long-name members (/N) -- any
member with a >15-char filename silently never linked. Only '/ '
(symbol index) and '//' (long-name table) are non-objects; /N
members index by content (names are never consulted). A member
that fails loadimage in the selective pull also stayed silently
unlinked with rc=0; it now reports and fails the link (rule 7).
wwstage w6l diagnostics ride the same .len idiom as the w6a sweep.