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.
wwstage parseint dropped the pre-multiply overflow guard the C twin
carries (cmd/wcc/lex.c:156, if (v > (u64)~0ULL / (u64)base)), so any
integer literal exceeding u64 was silently accepted mod 2^64 while
cstage loudly rejected with 'bad integer literal' — a rule-10 stage
divergence and a silent wrong constant. Port the guard before the
multiply-add; wwstage now rejects in lockstep with cstage.
lib/ww embeds into the w6c/wwdump combined.ww snapshots; both regen'd.
989_intoverflow_reject pins the reject-matrix on both driver twins.
