[GHC] #15472: GHC HEAD type inference regression post-"Remove decideKindGeneralisationPlan"

[GHC]

#15472: GHC HEAD type inference regression post-"Remove
decideKindGeneralisationPlan"
-------------------------------------+-------------------------------------
        Reporter:  RyanGlScott       |                Owner:  (none)
            Type:  bug               |               Status:  closed
        Priority:  highest           |            Milestone:  8.8.1
       Component:  Compiler (Type    |              Version:  8.5
  checker)                           |
      Resolution:  invalid           |             Keywords:  TypeInType
Operating System:  Unknown/Multiple  |         Architecture:
 Type of failure:  GHC rejects       |  Unknown/Multiple
  valid program                      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
-------------------------------------+-------------------------------------

Comment (by RyanGlScott):

 Thanks, monoidal. I've attempted to update the 8.8 Migration Guide
 ([https://ghc.haskell.org/trac/ghc/wiki/Migration/8.8?version=2#Kindgeneralizationchangesforlocaldefinitions
 here]) using this code as an example. goldfire, please shout if my
 explanation of the issue is wrong is misleading.

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/15472#comment:8>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler