[GHC] #14880: GHC panic: updateRole

[GHC]

#14880: GHC panic: updateRole
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        Reporter:  RyanGlScott       |                Owner:  goldfire
            Type:  bug               |               Status:  new
        Priority:  normal            |            Milestone:  8.8.1
       Component:  Compiler (Type    |              Version:  8.2.2
  checker)                           |
      Resolution:                    |             Keywords:  TypeInType
Operating System:  Unknown/Multiple  |         Architecture:
 Type of failure:  Compile-time      |  Unknown/Multiple
  crash or panic                     |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:  #15076            |  Differential Rev(s):  Phab:D4769
       Wiki Page:                    |
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Comment (by tdammers):

 The code as found on the `wip/T14880-accum` branch now validates, except
 for one stat failure: `haddock.base` allocates 6.5% more than expected. I
 don't know whether this patch introduces the regression or the head I
 rebased on though.

 This is exactly the same version as `wip/T1448-accum`, but rebased onto
 `master` and with some fixes to make it build again (the `Coercion` type
 has changed in the meantime, so I had to add another case branch).

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/14880#comment:100>
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