Fixed polyfills tests on IE 11.
Fixed polyfills tests on IE 11.

Dador/libjass,Dador/libjass,Arnavion/libjass,joshuabrown-ellation/libjass,joshuabrown-ellation/libjass,Dador/libjass,joshuabrown-ellation/libjass,Arnavion/libjass,Arnavion/libjass