Added Array.from unsafe optimization

[L2jLiga]

Only simple case Array.from(array) -> array

Closes #746

[aminya]

This seems safe to me. Could you provide a situation that this does not work?

[L2jLiga]

Sure, I can:

Array.from = function(...elements) {
  return elements;
}

console.log(Array.from([1]));

expected: [[1]]
actual: [1]

[aminya]

Array.from = function(...elements) {
  return elements;
}

Here you are assigning Array.from! We can do this for all of the JavaScript functions and break everything. I don't think this the responsibility of the minifier to prevent these cases. But I understand that tagging this as unsafe will prevent this 0.01% chance of breakage.

[L2jLiga]

Yes, Terser has several optimizations marked as unsafe because of this

[L2jLiga]

Ref: https://github.com/terser/terser#the-unsafe-compress-option

[fabiosantoscode]

Uh, why have I missed this?

Thanks!