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/r956_modqual_mq_nondestr_shadow/case.ww

@@ -0,0 +1,12 @@
+//ww:run-exit 10
+package beta;
+export fn dup() (i64, i64) = { return (3i64, 7i64); };
+package main;
+import beta;
+export fn main() i32 = {
+	let r = beta.dup();
+	if (r.1 != 7i64) { return 1; };
+	return (r.0: i32) + (r.1: i32);
+};
+package alpha;
+export fn dup() (i64, str) = { return (9i64, "wrong"); };