Part 5 - Add web-platform reftests for percentage resolution during intrinsic size computation.
All the tests pass in Google Chrome. They fail in the current Firefox Nightly
but will pass with the patches in this bug.
intrinsic-percent-replaced-{012,013,014}.html are adapted from the second
testcase in bug 1231059 comment 0.
intrinsic-percent-replaced-{015,016}.html are adapted from the testcase in bug
1800991 comment 2.
intrinsic-percent-replaced-017.html is adapted from bug 1910290 comment 7.
intrinsic-percent-replaced-018.html is adapted from dholbert's review comments
in https://phabricator.services.mozilla.com/D219523#inline-1222435
Differential Revision: https://phabricator.services.mozilla.com/D219524
bugzilla-url: https://bugzilla.mozilla.org/show_bug.cgi?id=1909761
gecko-commit: 4646bfebde8f95d2994a3336aeba92dd67a5b101
gecko-reviewers: dholbert