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/r774_accept_nested_wrapper/case.ww

@@ -0,0 +1,13 @@
+//ww:run-exit 42
+// Migrated from 774_tagged_widen_named_variant row accept_nested_wrapper.
+package main;
+type ax = !void;
+type inner = !(ax);
+type outer = !(inner);
+fn f() (size | outer) = {
+    let a: ax;
+    let i: inner = a;
+    let o: outer = i;
+    return o;
+};
+export fn main() i32 = { let r = f(); return 42; };