This includes a new test in the emoji loader, to see if the browser supports rendering Unicode 9.0 emoji, as well as an update to `twemoji.js`, to load Unicode 9.0 twemoji images.
The default CDN location for loading Twemoji images has changed, moving to a versioned subdirectory. This allows updates without needing to purge the CDN.
Fixes#37361.
git-svn-id: https://develop.svn.wordpress.org/trunk@38087 602fd350-edb4-49c9-b593-d223f7449a82