[csswg-drafts] Pull Request: [css-values] sin and cos can reach -1

ewilligers has just labeled a pull request from ewilligers for https://github.com/w3c/csswg-drafts as "css-values-4":

== [css-values] sin and cos can reach -1 ==
Use minus sign instead of hyphen.

Use increasing order for tan, improving consistency
as we use increasing order for sin and cos.


See https://github.com/w3c/csswg-drafts/pull/4112