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/r827_str_eq_empty/case.ww

@@ -0,0 +1,10 @@
+//ww:run-exit 1
+// Migrated from 827_str_eq row empty.
+package main;
+import strings;
+export fn main() i32 = {
+	let a: str = "";
+	let b: str = strings.dup("");
+	if (a == b) { return 1; };
+	return 0;
+};