add challenge scripts

js/07_weird_assembly_machine.js

@@ -0,0 +1,15 @@
+let f;
+
+async function prepare() {
+    const get = fetch('07_weird_assembly_machine.wasm');
+    const obj = await WebAssembly.instantiateStreaming(get);
+    f = obj.instance.exports.f;
+}
+
+function onClick() {
+    if(n >= 10n**18n) {
+        return;
+    }
+    n++;
+    x = BigInt.asUintN(64, f(x, n));
+}