Content fields using Alloy Editor do not render properly in IE11

• Type: Bug
• Status: Closed
• Resolution: Fixed
• Affects Version/s: Master
• Fix Version/s: 7.1.0 Beta 3, 7.1.X, Master
• Component/s: Frontend Infrastructure
• Labels: None
• Fix Priority: 5
• Browsers:
  Internet Explorer 11
• Sprint: S01E12 - Alien
• Git Pull Request: https://github.com/brianchandotcom/liferay-portal/pull/59365

There are a couple of UI issues documented here but I think they have the same root cause.

Steps to reproduce:
1. Navigate to Blogs widget
2. Click on New Entry
3. Fill out required fields (title, content fields)

Expected result 1:
When the user clicks into the content field, an Alloy Editor icon appears (which, when clicked, opens a toolbar)

Actual result 1:
No icon appears.

4. Click Publish

Expected result 2:
Blog entry is published.

Actual result 2:
Blog entry is not published. The content field apparently does not recognize the text added to it. The validation text under content field appears: This field is required

No console or browser errors appear.

This also happens with Knowledge Base and every other component that uses Alloy

Reproduced on:
Tomcat 9.0.6 + PostgreSQL 9.6.
Portal master GIT ID: cfb29a91916e6a4a42a38e279e3070c0d019b399
Browser: IE11