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/r989_intoverflow_u64max_dec_ok/case.ww

@@ -0,0 +1,7 @@
+//ww:run-exit 7
+package main;
+export fn main() i32 = {
+	let x: u64 = 18446744073709551615u64;
+	if (x == 18446744073709551615u64) { return 7; };
+	return 0;
+};