Make `ww test --sep` work the Hare +test way: the -T synth test-main emits a
qualified test.run, and the test package is injected as an ordinary
separately-compiled dependency instead of splicing lib/test source into a
flat unit. Additive — combined stays the default and 910/997 are untouched
(their migration is M4 E2).
- compiler synth (both stages): the -T main emits N_DOT test.run plus a
synthetic N_USE "test"; cmd/wcc/check.c + selfhost/cmd/wcc/check.ww.
- driver (both stages): build_one_sep gains is_test, injects the test package
as a root dep, and passes -T to the root; do_test --sep routes a single-file
test through the sep producer; cmd/ww/main.c + selfhost/cmd/ww/main.ww.
- 989_septest_run gate: ww test --sep on both stages, run-exit + cs==ww
byte-id of the sep .s, non-vacuous.
The synth's test.run is left ty_err by the checker in both regimes (lib/test's
run is scope-keyed under "" not "test"; cgen emits the correct CALL via run's
//ww:module test directive) — wwstage tolerates it like cstage (rule-10). The
genuine fix, module-keying run under sep so the call type-resolves, is #80.
w6c_ww/wwdump_ww/ww_ww move (their embedded source changed); w6a_ww/w6l_ww and
the combined codegen output are unchanged.