[GHC] #14691: Replace EvTerm with CoreExpr

[GHC]

#14691: Replace EvTerm with CoreExpr
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        Reporter:  nomeata           |                Owner:  (none)
            Type:  task              |               Status:  new
        Priority:  normal            |            Milestone:
       Component:  Compiler (Type    |              Version:  8.3
  checker)                           |
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  None/Unknown      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
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Comment (by nomeata):

 Ok, `wip/14691` has a complete refactoring. Time to address the fallout,
 and advise is welcome…

 I get
 {{{
 libraries/base/Data/Typeable/Internal.hs:1:1: error:
     GHC internal error: ‘mkTrCon’ is not in scope during type checking,
 but it passed the renamer
 }}}

 It seems that this code:
 {{{
 ds_ev_typeable :: MonadThings m => Type -> EvTypeable -> m CoreExpr
 ds_ev_typeable ty (EvTypeableTyCon tc kind_ev)
   = do { mkTrCon <- lookupId mkTrConName
 …
 }}}
 does not quite work when the current module is `Data.Typeable.Internal`,
 which is where `mkTrCon` is defined. Do I need a smarter `lookupId` that
 checks if the given `name` is supposed to be defined in the current
 module, and then uses the local name, rather than trying to find the
 global name?

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/14691#comment:6>
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