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/r946_structparam_f32f32_arg_fallback/case.ww

@@ -0,0 +1,9 @@
+//ww:run
+package main;
+type pf32 = struct { a: f32, b: f32 };
+fn use(s: pf32) i64 = { return (s.a: i64) + (s.b: i64); };
+export fn main() i32 = {
+	let s: pf32 = pf32 { a = 3.0f32, b = 5.0f32 };
+	if (use(s) != 8) { return 1; };
+	return 0;
+};