wwstage over-rejects harec's flexible-rune-const narrow (rune lit
promotes into any int whose range fits — harec check.c:1910,
types.c promote_flexible); explicit cast until that promotion lands
in ww (#29, revert to bare '\\' then). With the enum-as fix fnmatch
is byte-identical across stages: 989 #59.14 graduates
M_WWREJECT -> M_ID, transferring 972's cstage 8/8 behavior to the
provably-identical wwstage binary — the dark-regression gate. (#29)