[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 Joachim Breitner <mail@…>):

 In [changeset:"0e022e56b130ab9d277965b794e70d8d3fb29533/ghc" 0e022e5/ghc]:
 {{{
 #!CommitTicketReference repository="ghc"
 revision="0e022e56b130ab9d277965b794e70d8d3fb29533"
 Turn EvTerm (almost) into CoreExpr (#14691)

 Ideally, I'd like to do

     type EvTerm = CoreExpr

 and the type checker builds the evidence terms as it goes. This failed,
 becuase the evidence for `Typeable` refers to local identifiers that are
 added *after* the typechecker solves constraints. Therefore, `EvTerm`
 stays a data type with two constructors: `EvExpr` for `CoreExpr`
 evidence, and `EvTypeable` for the others.

 Delted `Note [Memoising typeOf]`, its reference (and presumably
 relevance) was removed in 8fa4bf9.

 Differential Revision: https://phabricator.haskell.org/D4341
 }}}

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/14691#comment:27>
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