Reject helpers checked only rc!=0, so a SEGFAULT (exit 139, or the
driver's "w6c failed" exit 1) counted as a clean reject -- a wwstage
crash could pass vacuously (it did, latently, on bodied bare-... pre
#11). Every reject row now captures stderr and requires the actual
diagnostic substring (rc!=0 AND strstr) across all 16 reject tests; a
crash emits no diagnostic, so it now fails. This is the
differential-reject backstop (#15): both stages must cleanly reject
with the expected message.
Two genuine cstage/wwstage diagnostic-body divergences are documented
inline via per-stage substrings, not papered over (845 tuple parse,
catA_f2 tuple arity); catalogued in #21.
parsefile's recovery fallback chewed an unrecognized top-level
construct to the next ';' without emitting an error or bumping p.errs,
so a typo'd keyword / stray token silently vanished from the AST and
the build succeeded rc=0 with the declared work gone — no link error
catches a dropped @test or unreferenced exported fn. The C twin
(parse.c:1395-1400) errorf+p->errs++ and rejects. Emit errmsg in the
fallback arm; wwstage now rejects in lockstep with cstage.
lib/ww embeds into the w6c/wwdump combined.ww snapshots; both regen'd.
989_unknowndecl_reject pins the reject-matrix on both driver twins.
