Preparing for a review of pattern synonyms

[Dr. ERDI Gergo]

Hi,

I believe I've finished implementing version 1 of pattern synonyms (i.e. 
everything described in #5144, minus the things in #8581, #8582, #8583 and 
#8584). I've discussed the way forward with SPJ and he suggested because 
of the cross-cutting nature of the patch, I should wait a reasonably long 
time (~1 month) after 7.8 is branched off for things to settle, and 
then formally submit it for review.

So my question is, is there anything I can do in the meantime, in 
preparation for the review? The code is available at 
https://github.com/gergoerdi/ghc. I've also added some tests 
to the testsuite (https://github.com/gergoerdi/ghc-testsuite), and 
updated the wiki pages at 
https://ghc.haskell.org/trac/ghc/wiki/PatternSynonyms and 
https://ghc.haskell.org/trac/ghc/wiki/PatternSynonyms/Implementation.

Thanks,
 	Gergo