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/r951_defdim_xmod_pathmax/case.ww

@@ -0,0 +1,11 @@
+//ww:run-exit 77
+package main;
+import os;
+def MAX: i32 = os.PATH_MAX - 1;
+type t = struct { b: [MAX]u8, end: i32 };
+export fn main() i32 = {
+	let s: t;
+	s.b[4094] = 7u8;
+	s.end = 77;
+	return s.end;
+};