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/r783_amp_fn_assign_neg_launder/case.ww

@@ -0,0 +1,10 @@
+//ww:error "not assignable"
+// A materialized *fn remains nominally distinct from *reader.
+package main;
+type reader = fn(x: i32) i32;
+fn rd(x: i32) i32 = { return x + 1; };
+fn main() i32 = {
+	let p = &rd;
+	let s: *reader = p;
+	return 0;
+};