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/r775_reader_void_unsupported/case.ww

@@ -0,0 +1,12 @@
+//ww:run-exit 11
+// Migrated from 775_io_vtable_run row reader_void_unsupported.
+package main;
+import io;
+export fn main() i32 = {
+    let vt: io.vtable;
+    let v: io.stream = &vt;
+    let buf: [4]u8;
+    let bs: []u8 = buf[0:4];
+    let _r = io.read(v, bs);
+    return 11;
+};