patch 4 - Remove failure annotation for first-letter-width test that now passes.
Also add an extra first-letter-width testcase (based on a case that was still failing
with an earlier iteration of the fix).
Differential Revision: https://phabricator.services.mozilla.com/D211598
bugzilla-url: https://bugzilla.mozilla.org/show_bug.cgi?id=385615
gecko-commit: 36fc4e06713de8a11db3cd3180ad24733d6581cb
gecko-reviewers: layout-reviewers, emilio