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/r707_str_24b_after_arridx/case.ww

@@ -0,0 +1,14 @@
+//ww:run-exit 5
+package main;
+type ft = (i64 | str | bool);
+fn askstr(s: str) ft = { return s; };
+fn main() i32 = {
+    let arr: [3]i64 = [10i64, 20i64, 30i64];
+    let i: i32 = 1;
+    let _v: i64 = arr[i];
+    let a: ft = askstr("world");
+    let p: u64 = (&a): u64;
+    let p2: *i64 = (p + 16u64): *i64;
+    let w: i64 = *p2;
+    return w: i32;
+};