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/r809idx_nested_lit/case.ww

@@ -0,0 +1,5 @@
+//ww:run-exit 45
+package main;
+type inner = struct { a: u64, b: u64 };
+type outer = struct { in: inner, t: u64 };
+export fn main() i32 = { let a: [2]outer; a[1] = outer { in = inner { a = 3u64, b = 4u64 }, t = 5u64 }; return (a[1].in.b * 10u64 + a[1].t): i32; };