jquery.js parse error in IE8

[jqz]

This is a follow-up to #47020.

The minification of jquery.js in [45342] is not compatible with IE<=8.

The error is:

SCRIPT1028: Expected identifier, string or number
jquery.js (4,13727)

It's caused by

propFix:{for:"htmlFor",class:"className"}

because for and class, being reserved words, need to be in quotes.

I know that WordPress 5.2.x no longer supports IE8 (see #47761). However the change has been ported back as far as WordPress 4.5.x ([46027]), which I'm pretty sure is supposed to support IE8.

[jqz]

WordPress 4.5.x, 4.6.x and 4.7.x still need to support IE8 - see ​https://wptavern.com/wordpress-4-8-will-end-support-for-internet-explorer-versions-8-9-and-10