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/r660_i64_out_param_negative/case.ww

@@ -0,0 +1,4 @@
+//ww:run-exit 42
+package main;
+fn setneg(p: *i64) void = { *p = -16i64; };
+fn main() i32 = { let x: i64 = 0i64; setneg(&x); if (x == -16i64) { return 42; }; return 0; };