Part 3 - Add additional web-platform tests.
intrinsic-percent-replaced-024.html and intrinsic-percent-replaced-025.html
capture the testcases in bug 1926015.
intrinsic-percent-replaced-026.html is adapted from bug 1888262. This is a
pre-existing bug, not a regression. Unfortunately, it is still failing, and
requires further investigation. I add the testcase while I'm working on a
similar issue.
intrinsic-percent-replaced-027.html is a reduced testcase from virtualbox.org
(bug 1931491).
Differential Revision: https://phabricator.services.mozilla.com/D229579
bugzilla-url: https://bugzilla.mozilla.org/show_bug.cgi?id=1926015
gecko-commit: f6ac932f84a4512c7a1e9170ac455bc2b0a3c242
gecko-reviewers: dholbert