[window.html]
  expected:
    if (os == "win") and debug and fission: [ERROR, OK]
    if (os == "linux") and debug and not swgl: [ERROR, OK]
    [OK, ERROR]
  [transfer to and from an iframe should work]
    expected: FAIL

  [the same ReadableStream posted multiple times should arrive together]
    expected: FAIL

  [port.postMessage should be able to transfer a ReadableStream]
    expected: FAIL

  [window.postMessage should be able to transfer a ReadableStream]
    expected: FAIL
