[GHC] #14429: Remove constraint types from HsExtension, post TTG

[GHC]

#14429: Remove constraint types from HsExtension, post TTG
-------------------------------------+-------------------------------------
           Reporter:  alanz          |             Owner:  (none)
               Type:  task           |            Status:  new
           Priority:  normal         |         Milestone:
          Component:  Compiler       |           Version:  8.2.1
           Keywords:                 |  Operating System:  Unknown/Multiple
       Architecture:                 |   Type of failure:  None/Unknown
  Unknown/Multiple                   |
          Test Case:                 |        Blocked By:
           Blocking:                 |   Related Tickets:
Differential Rev(s):                 |         Wiki Page:
-------------------------------------+-------------------------------------
 Once Trees that Grow is landed on the hsSyn AST, remove the constraint
 types from `HsExtension.hs`

 Hopefully `DataId`, `HasSourceText`, `OutputableX` etc can all go.

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/14429>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler