wcc: Hare-style enum [storage] { ... } type

`type Foo = enum [intT] { NAME [= expr], ... };`. Storage defaults
to i32; members auto-increment from 0 (or last+1) when `= expr` is
omitted, and value expressions can reference earlier siblings —
enough surface for io::mode-style flag enums (`RDWR = READ | WRITE`).

`Foo.MEMBER` folds to an N_INTLIT in the checker, typed as the
named enum. Binops on enum values yield the same enum (type_eq on
the named pointer), so `mode.R | mode.W` is a `mode`. Enum ↔ int
is a reinterpret-only `as` cast — same register, no tag wrap — so
`mode.RDWR as i32` and `1 as mode` both work without runtime ops.

`is`/`?`/`!` are still tagged-union-only. CSP runtime (chan/proc)
is unchanged; only the type-system slot is touched here.

test/wcc/200_parse.c

@@ -167,6 +167,11 @@ main(void)
 		"fn ti(r: (i64 | i32)) bool = { return r is i64; };",
 		"fn ai(r: (i64 | i32)) i64 = { return r as i64; };",
 		"fn br(r: (i64 | str)) i32 = { if (r is i64) { return 1; }; return 0; };",
+
+		/* Hare-style enum types */
+		"type color = enum { RED, GREEN, BLUE, };",
+		"type mode = enum u8 { NONE = 0, READ = 1, WRITE = 2, RDWR = READ | WRITE };",
+		"type whence = enum i32 { SET = 0, CUR, END };",
 	};
 	int n = sizeof parses / sizeof parses[0];
 	for (int i = 0; i < n; i++) {