use strict; is not supported - Attempted to assign to readonly property

[azogheb]

When using "use strict"; there is an error " Attempted to assign to readonly property."

In https://github.com/web-animations/web-animations-js/blob/master/web-animations-next-lite.min.js

b["true"] = a;

[azogheb]

Has strict mode compatibility be resolved for this library?

[dstoc]

This is something to do with uglify's wrap option. Which produces

function(exports,global){global["true"]=exports;