V8 Runtime was added to Google Apps Script at February 7, 2020
In my environment, at February 7, 2020, when I opened the script editor of Google Apps Script, the following notification could be seen.
By this, I could notice that finally, the V8 Runtime has already been added to Google Apps Script. I think that this will be also the great news for a lot of users including me.
The detail of V8 Runtime can be seen at https://developers.google.com/apps-script/guides/v8-runtime.