(cherry picked from commit 4408ea7c9be1b3faefb5d68871ddd60f912a431b;
amended to add a trailing space to calc-missing-context.txt since we
don't have LadybirdBrowser/ladybird#1603 yet)
This matches the name in the CSS Typed OM spec. There's quite a lot
still to do to make it match the spec behavior, but this is the first
step.
(cherry picked from commit 76daba3069de4c184c6b2317d0c89b50f81a8c00)