Some expectations need to be updated now that url.host setters use IDNA2008. https://build.webkit.org/results/Apple%20High%20Sierra%20Release%20WK2%20(Tests)/r231110%20(4251)/imported/w3c/web-platform-tests/url/url-setters-pretty-diff.html
Created attachment 339037 [details] Patch
This was fixed in https://trac.webkit.org/changeset/231121/webkit
<rdar://problem/39812949>