wrong polyfill with IE11 ?

[cvlmtg]

Configuration:

• Web browser and its version: IE11
• Operating system and its version: Windows 7
• PDF.js version: not sure, but probably >= 2.0.0
• Is a browser extension: no

Steps to reproduce the problem:

1. open https://mozilla.github.io/pdf.js/web/viewer.html
2. try to use Array.prototype.includes()

What is the expected behavior? (add screenshot)

[1,2].includes(1) should return true, not false

[yurydelendik]

fwiw, the polyfill comes from core-js library

[cvlmtg]

@yurydelendik unless I completely misunderstood something, according to the core-js author the fault is not in his polyfill:

babel/babel#7419

(please look the last comment on that issue)