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/r71_arrlit_str_lens/case.ww

@@ -0,0 +1,9 @@
+//ww:run-exit 5
+package main;
+fn main() i32 = {
+	let a: [3]str = ["hi", "byebye", "x"];
+	let p: i32 = a[0].len: i32;
+	let q: i32 = a[1].len: i32;
+	let r: i32 = a[2].len: i32;
+	return p * 100i32 + q * 10i32 + r;
+};