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/r961_pos_ptr_opaque/case.ww

@@ -0,0 +1,11 @@
+//ww:run-exit 42
+package main;
+fn id(p: *opaque) *opaque = { return p; };
+export fn main() i32 = {
+	let n: i32 = 42;
+	let po: *opaque = (&n): *opaque;
+	let back: *i32 = id(po): *i32;
+	let w: i32 = size(*opaque): i32;
+	if (w != 8) { return 1; };
+	return *back;
+};