wwi_emit took the .wwi `package` leaf from the first primary decl's module tag;
a fully empty primary module body (zero decls) had none, so the leaf stayed the
literal default "main" and the importer rejected it ("package main does not
match import path <leaf>"). The module identity is only available at parse time
(curmod is overwritten by imported //ww:module sections before emit), so stamp
the primary path onto the N_FILE node (TK_MODULE and TK_MODRESET rp!=NULL sites,
only-if-empty so a bare-reset `package main` root stays "main") and, when the
decl-scan finds no leaf, fall back to that stamped path. Symmetric cstage+
selfhost; both detect scan-miss via the same found-flag so the emitted .wwi
stays byte-identical.
Regression: test/wcc/989_wwileaf_run.c, table-driven over {empty body,
comment-only, nested a.b.c} decl-less shapes, non-vacuity proven.
Hojun-Cho
6525e137ae