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_write_i64/case.ww

@@ -0,0 +1,4 @@
+//ww:run-exit 42
+package main;
+type pt = struct { x: i64, y: i64 };
+fn main() i32 = { let s: pt = pt { x = 0i64, y = 0i64 }; let p: *pt = &s; (*p).x = 7i64; (*p).y = 35i64; return (s.x + s.y): i32; };