Any messages to the user which are echo-ed out in the test bootstrap will generally display on a command-line interface.
The *nix specific `"\n"` line ending will be ignored on Windows, making the messages less readable.
For new lines in CLI messages, `PHP_EOL` should be used instead.
This was already done in a few places in the script, but not consistently so. Fixed now.
Follow-up to [UT882], [UT890], [44723], [45020], [48592], [49535], [51560].
Props jrf.
See #53363.
git-svn-id: https://develop.svn.wordpress.org/trunk@51581 602fd350-edb4-49c9-b593-d223f7449a82