Improve handling of [/Pattern] cs.
Improve handling of [/Pattern] cs.

Treat "[/Pattern] cs" as being /Pattern cs. They do the same, so
send them both as the same simplified form. This helps reduce
complexity in the filters.

ArtifexSoftware/mupdf,ArtifexSoftware/mupdf,ArtifexSoftware/mupdf,ArtifexSoftware/mupdf,ArtifexSoftware/mupdf,ArtifexSoftware/mupdf,ArtifexSoftware/mupdf,ArtifexSoftware/mupdf