Hojun-Cho
ada99973ee
Adds unifyarith / binoptype / unoptype mirroring cstage cmd/wcc/check.c:580-596, 598-640, 642-687. Two new exprtype arms stamp e.type_ for N_BIN and N_UN via the same tinfofornode pattern as A.6.1.1/.2. unifyarith: untyped+untyped (prefer float), untyped+typed (typed via isassignable), typed+typed (typeeqast), fallback ltn. binoptype: ptr arith (ptr±int → ptr, ptr-ptr → i64), bitwise/ arith → unifyarith, comparison + logical → bool. unoptype: deref (resolvealias+unwrapbang then N_TPTR.lhs), addrof → *T with slice/str pseudo-field .len/.cap widening to *i64 (mirrors check.c:672-682), unary +/-/^/!. Wwstage stays silent on operator-type errors per existing checker discipline; cstage flags the same shapes. Verified 132/132 incl. 995_self_rebuild byte-identity.