IE11, core-js@3.6.4, String#split() unexpected behavior

Repro steps for (zloirock/core-js#751) IE version: 11.657.18362.0

Description

String#split() returns incorrect output in IE11 if imported and loaded twice on a page

Expected

"test".split(/^|\s+/); //["test"]

Actual

"test".split(/^|\s+/); //["t","e","s","t"]

How to reproduce

1. Clone this repository
2. Install packages (ex. yarn install)
3. Build (ex. yarn build)
4. Open index.html in IE