Proposal: Associating pattern synonyms with types

Dear devs, There has been a bit of discussion on #10653 about extending exports to allow users to associate pattern synonyms with types (just like ordinary data constructors). There is a section on the wiki which describes the problem and the proposed behaviour. https://ghc.haskell.org/trac/ghc/wiki/PatternSynonyms#Associatingsynonymswit... Any comments would be appreciated before I start the implementation. Please read all the way to the bottom past the examples as their are a few sections of clarification which might answer your question. Matt