Memory leak in WeakMap

[kasonyang]

Hi, I found a new bug in weak map. A key can not be free when it is only referenced by it's value.

For example:

const map = new WeakMap();

function test() {
    const k = {
        text: "a".repeat(1000)
    };
    map.set(k, {k});
    os.setTimeout(test, 0);
}

test();

Another example（build with webpack)

import {ref} from "@vue/runtime-core";

const sysInfo = ref({});

async function updateInfoLoop() {
  sysInfo.value = {
      time: new Date(),
  };
  setTimeout(updateInfoLoop, 16);
}

updateInfoLoop();