Ensure that proxying wrapped functions preserves checks

test/built-ins/ShadowRealm/prototype/evaluate/returns-proxy-callable-object.js

@@ -22,4 +22,11 @@ new Proxy(fn, {});
 
 assert.sameValue(typeof proxyCallable, 'function', 'wrapped proxy callable object is typeof function');
 assert.sameValue(proxyCallable(), 42, 'wrappedpfn() returns 42');
-assert.sameValue(proxyCallable instanceof Proxy, false, 'the wrapped function "hides" the proxy instance');
+assert.sameValue((new Proxy(proxyCallable, {}))(), 42, 'wrapped functions can be proxied');
+
+const getSecret = r.evaluate(`(obj) => { return obj.secret }`);
+const secretObj = { "secret": 496 };
+const dispatchToUnderlying = {
+  apply: (target, this_, args) => { return target(args); }
+};
+assert.throws(TypeError, () => (new Proxy(getSecret, dispatchToUnderlying))(secretObj), 'Proxying a wrapped function and invoking it still performs boundary checks');