test/wcc/data: grow the declarative compiler corpus to 1,224 fixtures

The r-prefixed waves absorb the runtime, reject, and byte-compare rows
of the migrated native carriers; each fixture is one directory with one
case.ww and a //ww:error, //ww:compile, //ww:run, or //ww:run-exit
directive covering both frontends.

test/wcc/data/r695_match_bind_slice_control/case.ww

@@ -0,0 +1,19 @@
+//ww:run-exit 3
+package main;
+type pair = struct { x: i64, y: i64, z: i64 };
+type tag = ([]u8 | pair);
+type holder = struct { e: tag, mark: i32 };
+fn main() i32 = {
+	let raw: [8]u8;
+	raw[0] = 1u8; raw[1] = 2u8; raw[2] = 3u8;
+	let h: holder;
+	h.mark = 99;
+	h.e = (raw[0:3]: tag);
+	match (h.e) {
+	case let v: []u8 => {
+		if (v.cap != 8) { return 20; };
+		return v.len: i32;
+	};
+	case let p: pair => return -1;
+	};
+};