Add spec for constructor-less param

spec/fixtures/module/no-prototype.js

@@ -1,4 +1,10 @@
 const foo = Object.create(null)
 foo.bar = 'baz'
 foo.baz = false
-module.exports = {foo: foo, bar: 1234}
+module.exports = {
+  foo: foo,
+  bar: 1234,
+  baz: function () {
+    return 'hello'
+  }
+}