Object doesn't support property or method 'assign' when formatting html on IE11

[Zlatkovsky]

monaco-editor version: 0.16.0 / 0.16.1
Browser: Internet Explorer 11
OS: Windows

In Internet Explorer, right-clicking and selecting "Format Document" when the language is HTML causes an exception to be thrown:

Object doesn't support property or method 'assign'

TypeError: Object doesn't support property or method 'assign'
   at TemplatablePattern (https://script-lab-react-alpha.azurewebsites.net/external/monaco-editor-0-16-1/vs/language/html/htmlWorker.js:12230:3)
   at Tokenizer (https://script-lab-react-alpha.azurewebsites.net/external/monaco-editor-0-16-1/vs/language/html/htmlWorker.js:13378:3)
   at Beautifier.prototype.beautify (https://script-lab-react-alpha.azurewebsites.net/external/monaco-editor-0-16-1/vs/language/html/htmlWorker.js:12712:3)
   at style_html (https://script-lab-react-alpha.azurewebsites.net/external/monaco-editor-0-16-1/vs/language/html/htmlWorker.js:12409:3)
   at html_beautify (https://script-lab-react-alpha.azurewebsites.net/external/monaco-editor-0-16-1/vs/language/html/htmlWorker.js:13636:17)
   at format (https://script-lab-react-alpha.azurewebsites.net/external/monaco-editor-0-16-1/vs/language/html/htmlWorker.js:13749:9)
   at HTMLWorker.prototype.format (https://script-lab-react-alpha.azurewebsites.net/external/monaco-editor-0-16-1/vs/language/html/htmlWorker.js:15094:13)
   at BaseEditorSimpleWorker.prototype.fmr (https://script-lab-react-alpha.azurewebsites.net/external/monaco-editor-0-16-1/vs/base/worker/workerMain.js#html:9439:17)
   at SimpleWorkerServer.prototype._handleMessage (https://script-lab-react-alpha.azurewebsites.net/external/monaco-editor-0-16-1/vs/base/worker/workerMain.js#html:5982:17)
   at handleMessage (https://script-lab-react-alpha.azurewebsites.net/external/monaco-editor-0-16-1/vs/base/worker/workerMain.js#html:5968:58)

I can also repro it in the Monaco Playground in IE 11. Simply go to https://microsoft.github.io/monaco-editor/playground.html, switch to the HTML tab, press "Format Document", and you'll see the errors

Note that currently, the Monaco Playground uses build 0.16.0, which has another issue that was just recently fixed in 0.16.1. So the fact that the context menu does not close, and the errors related to the "remove" method, are related to that other issue (#1357) and are a red herring. But the assign one is the one that's relevant for this bug

[Zlatkovsky]

Great! @aeschli, will you or your team be able to release an updated 0.16.2 version with the fix? Until then, I am blocked on using the latest Monaco editor. Thanks for your time!

[aeschli]

@alexandrudima Can we make a new build?