MessageChannel is not defined in encodeInto.any.js

[AtticusYang]

• Version: v13.0.0-pre
• Platform:Mac
• Subsystem:

I try to finish the feature Add TextEncoder.prototype.encodeInto , after finish the feature , i test with command
python tools/test.py wpt/test-encoding

I meet the failure as followed

[FAILURE] encodeInto() and a detached output buffer
MessageChannel is not defined
ReferenceError: MessageChannel is not defined
at Test. (node/test/fixtures/wpt/encoding/encodeInto.any.js:142:3)

encodeInto.any.js

142   new MessageChannel().port1.postMessage(buffer, [buffer]);
143   ({ read, written } = new TextEncoder().encodeInto("", view));

[AtticusYang]

@joyeecheung , thanks.

[AtticusYang]

add below code in test/wpt/test-encoding.js and fix the bug.

const { MessageChannel } = require('worker_threads');

runner.defineGlobal('MessageChannel', {
  get() {
    return MessageChannel;
  }
});