Bug fix: do not convert computed property

[uhyo]

Great work!

I found a bug which yields wrong result when converting an object with computed property.
It is very likely that a computed property name depends on runtime information, so this PR fixed this bug by not converting such object literals.

Thank you!

Bug reproduction:

// before
const obj = {
    hi: "hi",
    ["foo"]: "foo"
}

console.log(obj.foo); // => "foo"

// after
const obj = JSON.parse('{"hi":"hi","undefined":"foo"}');
console.log(obj.foo); // => undefined

[nissy-dev]

I didn't consider such a computed property...
Thank you for finding & fixing this bug 🙇