This file used the old style with type signatures
separated from the code. As far as I understand
the idea was to generate PostScript files from
the source. I think the idea was abandoned and
this more modern style is more common in the
codebase.

Test Plan: it still compiles

Reviewers: austin, simonmar, bgamari

Reviewed By: simonmar, bgamari

Subscribers: thomie

Differential Revision: https://phabricator.haskell.org/D2383