Unix vs. Windows EOL style mismatches can cause misleading failures in tests using the heredoc syntax (`<<<`) or multiline strings as the expected result.
Follow-up to [48466], [50995], [51079].
See #52625.
git-svn-id: https://develop.svn.wordpress.org/trunk@51135 602fd350-edb4-49c9-b593-d223f7449a82