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/r75_alloc_str_readback/case.ww

@@ -0,0 +1,5 @@
+//ww:run-exit 209
+package main;
+import rt;
+type holder = struct { s: str };
+fn main() i32 = { let p: *holder = alloc(holder { s = "hi" })!; let sum: i32 = 0; let i: i32 = 0; for (i < p.s.len) { sum += p.s[i]: i32; i += 1; }; return sum; };