all: Add js wasm for reference

exec.js

@@ -0,0 +1,11 @@
+const fs = require("fs")
+
+async function run() {
+    let code = fs.readFileSync(process.argv[2])
+    let module = await WebAssembly.compile(code)
+    let instance = await WebAssembly.instantiate(module, {})
+    let ret = instance.exports.app_main()
+    console.log(ret)
+}
+
+run()