Follow-up of bug 1795630 for some crashtests that were not in `mathml`
directories. The list was extracted in a subjective way from [1] by
looking at some tests that seem to contain essentially MathML with
some simple HTML or CSS. The changes to `crashtest.list` files have
been generated by [2].
[1] https://searchfox.org/mozilla-central/search?q=%3Cmath%7Cmathml&path=crashtest&case=true®exp=true
[2] `for file in $(^Ct ~/list-of-tests.txt); do D=$(dirname $file); F=$(filename $file); sed -i "/$F/d" $D/crashtests.list; done`
Differential Revision: https://phabricator.services.mozilla.com/D203614
