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/r812_assign_deref/case.ww

@@ -0,0 +1,4 @@
+//ww:run-exit 27
+package main;
+type pt = struct { x: size, y: size, z: size };
+export fn main() i32 = { let guard1: size = 111: size; let d: pt = pt { x = 0: size, y = 0: size, z = 0: size }; let guard2: size = 222: size; let s: pt = pt { x = 8: size, y = 9: size, z = 10: size }; let p: *pt = &d; *p = s; if (guard1 != 111) { return 98; }; if (guard2 != 222) { return 97; }; return (d.x + d.y + d.z): i32; };