Standard Bundler is unable to handle mutable exports

[Protryon]

Given the modules:

// renaming.js
import {x, setX} from '/root/renaming_dep.js';
var tempX = x;
setX(10);
var result = tempX + x;

//renaming_dep.js
export var x = 5;
export function setX(y) {
    x = y;
}

The standard bundler does not provide the correct output of 15 for the value of result in renaming.js, as expected by the spec, or other implementations.

Module piercing does not have this issue.