Mostly, removing things that were never intended to be exported publicy.
BREAKING CHANGE:
The following are no longer publicly exported APIs. They were intended as internal
utilities and you should use your own util:
```
browserDetection,
dispatchEvent,
el,
normalizeCSS,
stringifyElement,
expect (and custom matchers for Jasmine)
```
BREAKING CHANGES:
`containsRegexp` is no more exported from `@angular/core/testing`. It should not have been part of the public API in the first place.