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/r690_amp_dot_slice_field_ptr/case.ww

@@ -0,0 +1,8 @@
+//ww:run-exit 71
+package main;
+type wrap = struct { s: []u8, x: i32 };
+fn main() i32 = {
+	let arr: [4]u8; let w: wrap; w.s.len = 4; w.s.cap = 4;
+	let pp: **u8 = &w.s.ptr; *pp = &arr[0]; arr[0] = 71;
+	return w.s.ptr[0]: i32;
+};