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/r702_deref_read_i32/case.ww

@@ -0,0 +1,4 @@
+//ww:run-exit 6
+package main;
+type box = struct { a: i32, b: i32, c: i32 };
+fn main() i32 = { let s: box = box { a = 1, b = 2, c = 3 }; let p: *box = &s; return (*p).a + (*p).b + (*p).c; };